Role of MOFs in CO2 chemical conversion; Photocatalytic and electrocatalytic CO2 reduction; Role of linkers and metals in CO2 chemical conversion; and MOF composites and films in CO2 conversion.
In this review, we analyze the emerging field of metal–organic frameworks (MOFs) as catalysts for chemical conversion of CO2, with examples ranging from heterogeneous CO2 organic transformation to heterogeneous CO2 hydrogenation, from photocatalytic to electrocatalytic CO2 reduction. We also discuss the role of MOF composites and films in CO2 transformation. Our goal is to have an instrument useful to identify the best MOFs for CO2 conversion.
The recycle of CO2 to produce useful chemicals through carbon capture and utilization (CCU) technologies is an economically attractive approach to overcome the global warming issue and make sustainable development.1 Chemical fixation,2 photocatalysis and electrocatalysis,3,4 and hydrogenation5 are major utilization technologies employed to convert CO2 into valuable products, such as cyclic carbonates, which are attractive precursors for the industrial application. Moreover, the high abundance and easy-to-handle-feedstock of CO2 make it a suitable starting reagent for the CCU industry. However, the low reactivity of CO2 under standard conditions is one of the major factors that cause limits to its use, which required high-energy input for C=O bond cleavage (C=O bond enthalpy +805 kJ/mol).4 Over the last two decades, the catalytic materials used as heterogeneous catalysts to CO2 conversion, in this contexts, include metal oxides,6 zeolites,7 silica, porous materials,8 and activated carbon.2 However, energy cost, low efficiency, and poor recyclability combined with short lifetime are the major factors that limit their practical applicability. Metal–organic frameworks (MOFs) have been studied as attractive materials not only in gas adsorption but also in heterogeneous catalysis. Heterogeneous MOF-based catalysts are extremely advantageous over conventional homogeneous catalysts in terms of recyclability and ease of catalyst removal.9,10 High surface area, tunable pore size, and versatile surface chemistry of MOFs are powerful features to develop catalytic materials with performing catalytic activity to energetically efficient conversion of CO2.
This review focuses on the recent progresses in the chemical transformation of CO2 describing the three main categories in which MOFs are applied as heterogeneous catalysts. Specifically, we have discussed about conversion of CO2 and epoxide to form cyclic carbonate, electrocatalytic, or photocatalytic reduction of CO2 and CO2 fixated in MOFs or in terminal alkynes.
Heterogeneous CO2 organic transformation
Direct transformation of abundant CO2 to valuable chemicals is of great importance from the viewpoints of environmental and green chemistry. Heterogeneous catalysis constitutes an active and important field in MOFs science. The catalytic sites contained in MOF range from open metal sites and active (differently functionalized) organic ligands to pore of different sizes and chemically favorable environments acting as a nanoreactor for the CO2 transformation and useful to improve catalytic efficiency. MOFs are able to capture a high concentration of CO2 around the active catalytic sites by CO2 adsorption, ensuring high catalytic performance even in a mixed-gas environment with low CO2 concentration.
MOFs can chemically transform the CO2 as heterogeneous catalysts through three main different processes: chemical fixation of CO2 with epoxides into cyclic carbonates, CO2 hydrogenation, and the photochemical or electrocatalytic reductions of CO2 using MOFs or its composites and derivatives.
CO2 conversion into cyclic carbonates
The cycloaddition of CO2 to epoxides is a catalytic reaction in which an acid catalyst upon coordination to epoxide activates it toward a nucleophilic attack. The nucleophilic attack is typically carried out by the co-catalyst, often a tetraalkylammonium halide, to yield a halo-alkoxide intermediate which then reacts with CO2 through cycloaddition to yield the cyclic carbonate, regenerating the tetraalkylammonium halide co-catalyst.
A significant number of MOFs have been developed for the conversion of CO2 into cyclic carbonates via reaction with epoxides. The low catalytic efficiency as also the appearance of side products limited the applicability and to date, few catalytic systems have been widely investigated.11–13 MOFs are generally employed as co-catalyst in combination with ammonium or imidazolium salts, under mild reaction conditions. For example, Cr-MIL-101 has been employed in the presence of TBAB (tetrabutylammonium bromide) as co-catalyst in the conversion of styrene oxide. The Lewis acid in Cr-MIL-101 coordinates the O of the epoxide, which undergoes ring-opening through a nucleophilic substitution of the Br at the less hindered carbon.14 The catalytic role is attributed to the presence of Lewis acid sites, and on this basis, we can consider that the most active catalysts should have nodes based on early transition metals15 and lanthanides16,17 or mid group transition metals in high oxidation state. However, as these MOFs have nodes formed by multinuclear complexes, it is sometimes difficult to assign and determine the catalytic activity.
The catalytic activity of active sites of the porous 3D-framework [(Zn4O)2(Zn2)1.5(L1)6(H2O)3] exhibiting two kinds of SBUs including Zn2 paddlewheel and Zn4O tetrahedron units in which selective Zn(II) ions can be exchanged with Cu(II) and Co(II) ions via post-synthetic metal exchange has been investigated toward the CO2 cycloaddition reaction. Notably, the yield of the propylene carbonate, formed by propylene oxide-CO2 cycloaddition was higher in Zn-MOF 99% and lower in the analogous Co- (50%) and Cu-MOF (32%). The higher-binding energy of CO2 to metal sites in Zn-MOF and the lower energy gap between the HOMO of epoxy propane and the LUMO of CO2 on the active sites resulted in a high catalytic activity.18
A dual wall cage of [Zn6(TATAB)4(dabco)3(H2O)3]⋅12DMF⋅9H2O has been obtained by the interpenetration of two independent cages. The high density of Lewis acid sites in this MOF leads an efficiency for the cycloaddition of CO2 with propylene oxide at 100 °C and 1 atm, in the absence of co-catalyst and solvent up to 99% yield over 16 h.19
The Hf-based Hf-NU-1000 and the Zr-based Zr-NU-1000 have been investigated as catalysts for the cycloaddition reaction of styrene oxide with CO2. The Hf–O bond is more oxyphilic and stronger than the Zr–O one and thus worked as a stronger Brønsted acid. Therefore, Hf-NU-1000 showed a higher efficient catalytic activity than Zr-cluster-based for acid-catalyzed systems under ambient conditions, in the presence of TBAB co-catalyst (Fig. 1). The Hf-NU-1000 achieved a yield of 100% that has been attributed to the high density of Lewis acid sites and the relatively large pore size (13–29 Å).17 The efficiency of this MOF was shown to be higher concerning other MOFs with catalytically active metals centers such as HKUST-1, MOF-505, and MMPF-9.20,21
The Ni-based MOF Ni-TCPE-1 has been synthesized by incorporating a tetrakis(4-carboxyphenyl)ethylene moiety as the four-point connected node. Ni-TCPE-1 shows large single-walled nanotubes with exposed Ni2+ cations in which organic substrates can be adsorbed and the products can be easily transported. Ni-TCPE-1 exhibits high catalytic efficiency with >99% conversion of styrene oxide to styrene carbonate even under atmospheric pressure of CO2, at room temperature. Most important, the TON was of 35,000 for Ni-TCPE-1 achieved after 20 times of repeating the catalytic reaction.22 Nbo-type MOFs are also versatile catalysts for the synthesis of propylene and other mono-substituted cyclic carbonate, the total conversion of propylene oxide being observed after 48 h.23
A Zn(glutamate)-based MOF has been employed in the reaction of CO2 with propylene oxide and methylaziridine. Quantitative conversion and full selectivity were found only when ammonium salts were added to the reaction mixture, the MOF alone showing no activity.24
Two new adenine-based MOFs were used as heterogeneous catalysts for the fixation of CO2 into five-membered cyclic carbonates. The adenine-based MOFs formed by auxiliary dicarboxylates and unsaturated Lewis acidic metal centers Zn(II) and Cd(II) allow to get a significant conversion of epichlorohydrin at a low CO2 pressure (0.4 MPa) with a moderate catalyst (0.6 mol%)/co-catalyst (0.3 mol%) amounts, the selectivity being over 99% toward the ECH carbonate.25 Also, defects in the MOF structure and/or the defects on the MOF surface can catalyze the cycloaddition of epoxide with CO2 when the linkers are not catalytically active and the metal centers are coordinatively saturated. In most of the cases, the MOFs are Zn2+-containing materials.26–28 A different approach consist in to have not only nodes with acidic characters but also Lewis acid-containing linkers, resulting in a higher concentration of acid sites and hopefully in higher efficiency of the catalytic performance. For example, auxiliary linkers were subsequently added to PCN-900(Eu) by post-synthetic exchange to form isoreticular compounds with more metal chelating agents. The PCN-900(Eu)-CoTCPP-CoBPYDC exhibited higher conversion (93%) due to higher density of Eu3+ and Co2+ species which play an important role in the cycloaddition reactions of CO2 with epoxides.29
The Lewis acid site-rich nano-size Co-MOF showed 98.2% of conversion efficiency for converting propylene oxide into propylene carbonate at 50 °C and 1 atm CO2, whereas at 25 °C was relatively low (19.3%). Interestingly, the Co-MOF catalyst has been recycled five times without a significant loss of activity.30
The use of azamacrocycle23 as metalloporphyrin in the construction of new MOFs seems to result in overall catalytic efficiency.31 In nbo-type metal macrocyclic framework MMCF-2, six square faces of cuboctahedra cages have been Cu2+ decorated by metallated azamacrocycles. The additional active sites well oriented in the framework with higher density improve the catalytic activity (95.4%) for the cycloaddition of CO2 and propylene oxide in the presence of co-catalyst under ambient conditions. The number of active copper sites in the MMCF-2 resulted in 50% more than in the parent MOF-505, and therefore, the MMCF-2 catalytic activity was twice the efficiency than MOF-5 (48%).32 MOFs could be autonomous efficient catalysts where the Lewis acidic metal nodes can be used to activate the epoxides and the organic can be employed as “co-catalysts” to trigger CO2. For example, organic functional linkers with amine groups have been investigated for their catalytic activity toward the CO2 cycloaddition reaction.33–35 In fact, it seems that the introduction of Lewis basic functional groups such as amine into the organic linkers yield catalysts with acid-base pairs analogous to zeolites that have already demonstrated effective in CO2 cycloaddition. The production of OCs could be promoted by the concerted action of acidic and basic sites in the same catalyst (Fig. 2).36
In mild and green conditions, i.e., solvent and co-catalysts free, the amino-decorated bis(pyrazolate) MOF, Zn(BPZNH2), acts as a heterogeneous catalyst in the reaction between CO2 and activated epoxides C3H5XO bearing a pendant arm (X = Cl: epichlorohydrin; X = Br: epibromohydrin). Good conversion of 41% and 47% were recorded for –CH2Cl and –CH2Br, respectively (turnover frequency (TOF) = 3.4 and 3.9) (Fig. 3).37
A similar mechanism has been proposed for zirconium MOFs [Zr6O4(OH)4(TzTz)6]. This heterogeneous catalyst in the reaction of epoxides with CO2 under mild and green conditions gave a conversion of 74% to the corresponding cyclic carbonate with a TOF of 12.3 mmol per mmolZr per h.38
As for Zn(BPZNH2), the synergism of amine and Lewis acid sites in the UMCM-1-NH2 increased the CO2 conversion to 78% with high selectivity for propylene oxide. Moreover, the balance between pore size and accessible Lewis basic sites has been demonstrated to be essential for CO2 fixation at room temperature.39
In the LBSs-rich Zn-btz-MOF, the efficient enrichment of epoxides and CO2 in the nanoscale [Zn24] cages and limits the coordination of the Br– nucleophile to Zn(II) ion, allowed a completed CO2 conversion (>99%) into phenylethylene oxide within 12 h. The Zn-btz-MOF, recycled 10 times, has been employed to catalyze the cycloaddition of aziridines with CO2 at high temperatures and pressure.40 Also in the anionic Zn-MOF, the Lewis basic pyridyl sites and the effective cooperative process of the Lewis acidic site and the anionic framework for nBu4N+ ion permitted high catalytic efficiency for the cycloaddition of propylene oxide to form propylene carbonate in 92.1 % yield over 48 h.41
The honeycomb-like Ba-MOF with exposed Lewis acidic Ba2+ ions and the Lewis basic oxalamide increase the catalytic efficiency under the mild conditions as a recyclable heterogeneous catalyst.42
The combination of phenol, amino and triazine groups in JUC-1000 produces multiple sites able to form propylene carbonate in 96% under ambient conditions. The synergy of weak acids and bases sites improved the stability of JUC-1000 MOF due to the presence of buffering effect (−O−/−OH, −NH−/−NH+−, and −N=/−NH+=).43
A Cu-MOF based on lactam has been synthesized for an efficient conversion of CO2 into cyclic carbonates. The effect of lactam decorating pores with open Cu(II) site and TBAB as a co-catalyst allowed a high product yield for cycloaddition between CO2 and various epoxide.44 Another Cu(II)-based MOF, FJI-H14, with a high density of active sites and displaying high volumetric uptake and excellent CO2/N2 selectivity, was employed to catalyze cycloaddition of styrene oxide with the simulated flue gas (CO2:N2 = 15:85).45 Alternative approach concerned the immobilization of co-catalyst onto IRMOF-3 backbones using nucleophilic substitution of the amine group. The yield of propylene carbonate increased to 98% in 1.5 h with F-IRMOF-3.46
Ln-MOFs based on the tetra-topic linker benzoimidephenanthroline tetracarboxylic acid exhibit good adsorption of CO2 but moderate CO2 selectivity over N2 and CH4; however, they are catalytically active in the one-pot oxidative carboxylation of styrene and CO2 to give styrene carbonate under mild conditions.
The zeolitic imidazolate frameworks (ZIFs) where the metal plays the role of silicon and the heterocycle mimics the oxygen role47 are characterized by a large surface area and high porosity often combined with relevant mechanical, thermal, and chemical stability.48 ZIFs show a high affinity toward CO2. ZIF-95 has been employed as a catalyst in the CO2 chemical fixation into propylene oxide to yield the corresponding cyclic carbonate.49 In the presence of TBAB, good conversions were achieved at 80 °C whereas in the absence of a co-catalyst, a high propylene carbonate yield was achieved raising the temperature and employing longer reaction times.
The defect sites present across ZIF-68 crystals act as active sites in cycloaddition reactions. The small pore apertures of approximately 0.55 nm allowed the reaction taking place on the surface of the crystal where structural defects and uncoordinated active sites are present. The conversion efficiency achieved to 93% yield of styrene carbonate at 120 °C and 9.9 atm in green condition.19 However, defects in MOFs are not powerful approach for increasing the catalytic performance because these MOFs required high temperature and pressure for their catalytic activity.19
Another approach to accelerate the cycloaddition reaction under mild condition consists of the location of the halogen co-catalyst ions near the acidic reaction centers. In the imidazolium-functionalized FJI-C10 MOF synthetized upon the incorporation of the ionic ligand [(Etim-H2BDC)Br], the resulting ionic surfaces are effective to increase the CO2 interactions due to the dipole–quadrupole interaction. The large dipole moment of the CONH group facilitates dipole–quadrupole interactions between the acylamide groups and CO2, with NH⋯OCO hydrogen bond formation. The cycloaddition reaction between CO2 and epichlorohydrin catalyzed by FJI-C10 was almost complete (99.7%) with an enhanced selectivity of 88.2% within 24 h at 60 °C (Fig. 4).50
CO2 fixation in MOFs via carboxylation of terminal alkynes
Many catalytic systems have been applied in the carboxylation of terminal alkynes yielding products such as alkynyl carboxylic or esters with pharmaceutical and fine chemical applications.51 Very recently two MOFs assembled with multinuclear Gd- and Cu-cluster, possessing active catalytic centers [Gd3(IN)9(DMF)4] and [Cu12I12], respectively, showed excellent catalytic performance in the CO2 carboxylation reactions with terminal alkynes under 1 atm at mild conditions. The two multinuclear MOFs showing high thermal and solvent stability have been the first MOF-based materials in which no co-catalyst/additive has been used during the catalytic process.52
Efficient conversion of propargylic alcohols to α-alkylidene cyclic carbonates through a porous Ag(I)-based MOF, Ag-TCPE, in the presence of Ph3P has been reported. The decentralized silver (I) chains in the frameworks showed a specific alkynophilicity to activate C≡C bonds (both σ-complexation and π-complexation properties with terminal alkynes)53,54 of propargylic alcohol and subsequently cyclize it with CO2 (Fig. 5).55
Alkynophilic Ag(I) sites have been also incorporated in an organosulfonate-based MOF, TMOF-3-Ag, with a defective primitive–cubic (pcu) topology. The TMOF-3-Ag MOF has been tested for carboxylic cyclization of propargylic alcohols into α-alkylidene cyclic carbonates in the presence of DBU. The high yields (>86%) were essentially due to the synergic effect of organosulfonate showing high CO2 affinity and to the Ag(I) sites very active toward alkynes. Moreover, TMOF-3-Ag was also employed to catalyze the three-components reaction between propargyl alcohol, CO2 and primary amine to afford the corresponding carbamates, as well as oxazolidinones by the carboxylic cyclization of propargyl amines with CO2 (yields >97%).56
MIL-101 can act a host for growing Ag nanoparticles and the Ag@MIL-101 which shows a high CO2 uptake has been demonstrated to be an efficient heterogeneous catalyst for the transformation of terminal alkynes into propiolic acid derivatives in the presence of Cs2CO3 under 1 atm of CO2 (Fig. 6).57 A new nanocatalyst has been fabricated with Ag nanoparticles supported over a porous Co(II)-salicylate MOF. The resulting AgNPs/Co-MOF showed high catalytic activity in the carboxylation of terminal alkynes via CO2 fixation reaction to yield alkynyl carboxylic acids under very mild conditions.58
CO2 can be also successfully inserted into the aryl C–H bonds of dcppy ligand of UiO-67 yielding a functional MOF UiO-67(dcppy)-COOH, this result opening the door to use CO2 chemical fixation as a C1 building block to modify MOFs.59
Diamine-appended MOFs behave also as “phase-change” adsorbents, the CO2 adsorption isotherms shifting markedly with temperature. MOFs have been recently reported for which the adsorption step is an unprecedented cooperative process. Specifically, the reorganization of the amines into well-ordered chains of ammonium carbamates has been induced by CO2 insertion into metal-amine bond. The described results provide a mechanistic framework for designing highly efficient adsorbents useful to remove CO2 from various gas mixtures and yield insights into the conservation of Mg2+ within the ribulose-1,5-bisphosphate carboxylase/oxygenase family of enzymes.60
The flexible MOF decorated with NH2 groups [Cd3(L2)2(BDC)3]2 exhibits the cyclization reaction between CO2 and propargylamines with high TONs (9300) to construct five-membered urethane ring structures. The NH2 groups promoted an efficient ring closure to the oxazolidinones derivative, which was stable under the reaction conditions.61
Heterogeneous hydrogenation of CO2
Hydrogenation of carbon dioxide (CO2) to methane, methanol, alkyl formates, and formic acid is an effective strategy for CO2 utilization.62 The development of efficient catalytic CO2 hydrogenation processes operating at low reaction temperature and low pressure is today extremely important. In addition, homogeneous catalysts require expensive and difficult processes, whereas heterogeneous processes using MOFs are really advantageous as they can be appropriately structurally designed to contain substituents and groups able to coordinate and stabilize metal species able to efficiently catalyze the desired reaction.
CO2 methanation is generally catalyzed by transition metals, Ru-, Rh-, and Ni-based catalysts being the most active species.63 Very recently multi-metal composite oxides, hydrotalcite, and MOF-based catalysts have been investigated. Metal oxides due to low surface areas and non-porous structures exhibit limited intimate contact between reagents and active sites in the catalyst, whereas MOFs catalysts can play a more determinant role due to large accessible surface areas, reactive metal sites, and tunable pore functionalities. The main drawback affecting the use of MOFs is in their instability at high temperatures under the hydrothermal reaction conditions. A Ni-based catalyst prepared by high dispersion of Ni (41.8%) in MOF-5 and showing a surface area of 2961 m2/g demonstrated a greater activity and stability with respect to the benchmark Ni/SiO2.64 Also, a ZIF-67-derived Co-containing catalyst exhibits higher activity with respect to traditional Al2O3 supported species.65 It seems that CO2 converts to CO on the Pt actives sites, whereas methanation of CO occurs at the Co-active sites.66
A MOF-derived catalyst for CO2 methanation has been produced from Ru-impregnated Zr-MOF material. The resulting Ru-doped UiO-66 active catalyst converted CO2-rich streams at high gas flows conditions with a yield of 96%, and it was highly selective for CH4 (99%). In addition, low quantity of CO as by-product has been observed.67
Methanol is a very valuable intermediate chemical that can be produced catalytically. There has a big effort recently for a direct method in the preparation of methanol without the use of fossil fuels, but using CO2 already in the environment combined with H2 from renewable energy. It has been recently reported that the confinement of Cu–ZnO systems in MOFs can enhance performance and selectivity.68 For example, a highly effective PdZn alloy catalyst derived from Pd@zeolitic imidazolate framework (ZIF-8) has been prepared and investigated for the hydrogenation of CO2. The confinement of subnanometric Pd particles in the pores of ZIF-8 makes possible the formation of Pd–ZnO interfaces with strong metal–support interaction after simple pyrolysis under air condition. High methanol yields are observed and assigned to the formation of small-sized PdZn alloy particles after H2 reduction and a high number of surface O2 defects on ZnO.69 Cu NPs can be encapsulated in MOFs. Their strong interaction with the secondary structural units gave NPs@MOFs (Cu ⊂ UiO-6670 and CuZn@UiO-bpy71 exhibiting enhanced activity and 100% CH3OH selectivity).
Earth-abundant metals have been employed in the synthesis of MOFs suitable for the production of efficient material catalysts for CO2 conversion to ethanol. The cooperative presence of Cu sites on a Zr12 cluster in an MOF is important to activate hydrogen via bimetallic oxidative addition and promote C–C coupling yielding finally ethanol.72
MOF-derived catalysts where iron and iron oxides are dispersed in a carbon matrix can be easily prepared and used for catalytic activation of the hydrogenation of CO2 to hydrocarbons. An iron-based catalyst derived from pyrolysis of a modified ZIF-8 has been synthesized with the aim to hydrogenate CO2. The carbon encapsulated nanoparticles not only exhibit high activity but also selectivity to value-added hydrocarbons (C2–C4 and C5+).73 Other species have been obtained from the one-step pyrolysis of Fe-MIL-88B. Different catalytic performances are due to the transformation of the Fe species in the reaction condition, the higher catalytic performances achieved when Fe3O4 and χ-Fe5C2 are present in the catalyst.74 Also, an Fe3O4@ χ-Fe5C2 core–shell structure obtained by pyrolysis of an Fe-MOF based on carboxylate ligands has been investigated, and it has been found that the carbonates covered on the outer surface decompose to CO2 producing an active surface for catalytic turnover during FTS.75 The calcination of Fe-MIL-88B-NH2 gave a porous Fe3O4/carbon material possessing great resistance on temperature changing usable as supercapacitors.76
Encapsulation of the (tBuPNP)Ru(CO)HCl complex in UiO-66 has been obtained through aperture-opening events resulting from dissociative linker exchange reactions. The resulting [Ru]@UiO-66 showed catalytic activity for the hydrogenation of CO2 to HCOO−, exhibiting greater recyclability with no evidence of catalyst decomposition.77
Alternatively, the incipient-wetness impregnation has been used to support Ru on the Zr-MOF. The Ru/Zr-MOF was employed as a catalyst for CO2 hydrogenation with the assistance of dielectric barrier discharge plasma. In the hydrogenation, CH4 was selectively produced (95%). The catalyst is stable in plasma.78
Photocatalytic and electrocatalytic CO2 reduction
The photoreduction of CO2 into reusable chemicals is surely one of the most promising strategies to address the required energy and to reduce excessive CO2 emissions. MOFs have been recently reported as possible catalysts CO2 photoreduction due to their tailorable ability in CO2 and light adsorption. CO2 is a stable molecule and its reduction reaction is endothermic. Low CO2-conversion rates were generally observed and for this reason, it is interesting the possibility to develop efficient photocatalysts to accelerate the process. The photoreduction of CO2, driven by visible light or UV irradiation, activated by a photocatalyst with a suitable band structure can yield HCOOH, CO, HCHO, CH3OH, and CH4, always through a series of proton-assisted multi-electron reactions. MOFs can be employed both as photocatalyst and photocatalytic hosts to play a role in photocatalytic CO2 reduction. For example, it is possible to synthesize a variant of UiO-67 by using bpdc and [Re(CO)3(BPYDC)Cl] as organic linkers that show a catalytic activity three times higher active than that reported for the homogeneous catalyst [Re(CO)3(BPYDC)Cl].79
Several papers have reported the use of MOFs in photocatalysis. In particular, after light excitation, MOF-5 behaves as a semiconductor and it undergoing a charge-separation process.80 Appropriate HOMO-LUMO gap width to adsorb UV-visible light, light-harvesting electron-rich organic linkers as photon-absorption centers, and inorganic metal ions with variable redox states or unsaturated metal sites are three essential MOF features for photocatalysis application.
The choice of the organic linker and the inorganic metal cluster is a key step in the design of pure MOFs as photocatalyst. The electronics properties may be predicted based on the HOMO and the LUMO of the organic linker and on the metal centers with empty d orbitals, which overlap the LUMO of the organic linker, facilitates an efficient ligand to metal charge transfer (LMCT).81,82
Ti–O, Zr–O, and Fe–O clusters are generally the best choice as also amino-modified, photosensitizer-functionalized electron-rich conjugated organic linkers. MOFs containing variable valence metal ions coordinated to the oxygen of polycarboxylic ligands trap photoexcited electrons and show considerable reduction power to drive photocatalytic reduction in an efficient mode.83 MIL-125(Ti) has been employed in photocatalytic reduction of CO2, HCOO− being detected in MeCN with triethanolamine (TEOA) under 365 nm UV-light irradiation.84 Zr-based MOFs have been indicated as ideal porous MOF photocatalyst also due to the variable valence states (Fig. 7).85
The OH ligands can cooperate with neighboring catalytic active metal centers to boost photocatalytic CO2 reduction. MOFs bearing μ-OH ligands near to open Co centers showed CO selectivity up to 98% and TOFs of 0.059 s−1 in pure CO2 at 1.0 atm.86 The photocatalytic CO2 reduction of several MOFs has been investigated in pure CO2 in a mixture of MeCN and H2O as a solvent, under visible light and using [Ru(bpy)3]Cl2 as photosensitizer: CO was identified as the main product, its quantity increasing along with the irradiation time.87
Earth-abundant Fe-containing MIL-based MOFs exhibit photocatalytic activity for CO2 reduction to yield formate under visible-light irradiation. In these MOFs, the electron transfer from O2– to Fe3+ to form Fe2+, responsible for the photocatalytic CO2 reduction, was induced by direct excitation of the Fe–O clusters. MIL-101(Fe) seems to show the best activity due to the presence of unsaturated Fe sites in its structure.88
A solvent-free reaction for the photoreduction of CO2 catalyzed by Fe-MOFs has been reported and compared with the orthodox reaction. The environmentally friendly photocatalytic CO2 reduction showing a greater selectivity with respect to CO occurs at the gas–solid interface. The reaction procedure represents a possibility to address the CO2 emission problem.89
A porphyrin-based MOF, PCN-222, has been described selectively able to capture and further photoreduce CO2 with high efficiency under visible-light irradiation. The relationship between the photocatalytic activity and the electron–hole separation efficiency has been elucidated through mechanistic information gleaned from ultrafast transient absorption spectroscopy and time-resolved photoluminescence spectroscopy. PCN-222 effectively inhibits the detrimental, radiative electron–hole recombination thanks to the presence of a deep electron trap state.90
A robust Zr-MOF (NNU-28) has been synthesized, through a solvothermal reaction involving ZrCl4 and a dibenzoic acid anthracene derivative. NNU-28 exhibits a high surface area and a significant CO2 uptake that can be applied as a highly efficient visible-light responsive photocatalyst for the reduction of CO2 to formate. The high yield has been assigned to the synergistic effect of Zr6 metal clusters with the anthracene organic ligand for visible-light harvesting.91 Also, Fe88 and Ti84 MOFs NH2-MIL-based showed high activity for photocatalytic CO2 reduction through dual excitation pathways.
Low-cost CH3NH3PbI3 (perovskite QDs) were encapsulated in a Fe-porphyrin-based MOF (PCN-222 (Fex) to yield a composite photocatalyst exhibiting stability in reaction systems containing water. Very relevant is the proximity of QDs to the Fe catalytic site in the MOF allowing the transfer of the photogenerated electrons from QDs to the Fe catalytic site. The composite shows a record-high yield (1559 μmol/g) for photocatalytic reduction of CO2 to CO (34%) and CH4 (66%).92
Embedding Ti4+ ions into Zr–O clusters Zr6O4(OH)4 of UiO-66(Zr) enhanced the CO2 adsorption capabilities and increased the photocatalytic sites both being responsible of the improved photocatalytic performances.90 By calcination of the Ni–Zn bimetallic MOFs, ZnO/NiO porous hollow spheres with sheet-like subunits were prepared. The ZnO/NiO composites demonstrated the highest CH3OH evolution rate, which is about three times than that of pure ZnO with enhanced photocatalytic activity for CO2 recondition.93
Electrocatalysis is another important process to convert CO2 in useful products, which analogously to photocatalysis can be carried out at room temperature and low energy. Potential MOFs candidates in electrochemical CO2 should be a material where proton can be easily transported to the catalytic site and even possess a redox-active site to concentrate CO2.94 A proton conductive copper rubeanate MOF (CR-MOFs) was used for the electroconversion of CO2 to HCOOH in aqueous media by means of potentiostatic electrolysis. The final selectivity of HCOOH using CR-MOF was 98% significantly greater than the Cu electrode (38%). MOF-based electrocatalysts need to be deposited on the surface for electrocatalytic applications; we have discussed more in detail below.
MOF composites and MOF film in chemical conversion of CO2
MOF-based composites have been mainly explored to increase photocatalytic activity through the formation of a heterojunction useful to increase charge separation. For example, TiO2/MOF composites have been studied in an effort to improve their photocatalytic activity. The TiO2/HKUST-1 composite with approximately 33%wt of TiO2 was created by grafting of anatase phase TiO2 particles onto HKUST-1 (Cu3(BTC)2) microcrystals compared to HKUST-1. The CO2 capacity of the MOF was not inhibited by the presence of TiO2, though CO2 adsorption capacity of the material decreased by around a third. TiO2/ZIF-8 composites with various MOF loadings have been synthesized by forming ZIF-8 on a TiO2 film (mixed anatase and rutile phase) [Fig. 8(a)].95 An increase in MOF loading generates an increase of CO2 adsorption capacity of the composite and decreased charge recombination probed by PL.
ZIF-8 has been deposited onto Zn2GeO4 nanorods96 a semiconductor well-known as photocatalyst for CO2 reduction. CO2 adsorption isotherms have indicated that in the case of unmodified Zn2GeO4, the capacity was around double and in the Zn2GeO4/ZIF-8 nanorods was less than 50% compared to ZIF-8. Photocatalytic experiments with the composite showed a 62% increase in methanol production compared to Zn2GeO4, owing to higher CO2 adsorption and wider light absorption spectra [Fig. 8(b)].
In semiconductor photocatalysts, the presence of noble metals can lower the band gap and promote charge separation.97 The M-doped NH2-MIL-125(Ti) MOF has been prepared with Pt and Au98 that were found to exist as nanoparticle clusters bonded to the amine group on the organic linker. Photocatalytic experiments showed enhanced activity for photocatalytic HCOO− and H2 formation with Pt/NH2-MIL-125(Ti) under visible-light irradiation.
Carbon nitride (γ-C3N4) has been coupled to Co-ZIF-9. γ-C3N4 has been chosen as it is a noble-metal-free semiconductor and is photochemically stable.99 Carbon nitride nanosheets coupled with UiO-66 via an electrostatic self-assembly synthesis and under visible light in the presence of TEOA have been employed in the reduction of CO2 to CO.100
A Re-based MOF highly oriented thin film has been deposited onto a conductive FTO electrode by a liquid-phase epitaxy approach. The Re-SURMOF-based electrodes exhibit an extremely high Faradaic efficiency of 93 ± 5% as well as high selectivity for the reduction of CO2 to CO.101
The electrophoretic deposition of thin films of Fe porphyrin-based MOF-525 on FTO glass substrates has been investigated for electrochemical reduction of CO2. Fe-MOF-525 film possesses a high effective surface coverage of electrochemically addressable catalytic sites (~1015 sites cm−2). The chemical products of the reduction are mixtures of CO and H2 obtained with ~100% Faradaic efficiency.102
Several MOF-based composites have been extensively investigated in order to obtain high-performance materials as electrocatalyst for CO2 reduction.103 The adopted strategies include the increase in the number of exposed metal sites with respect to the surface, the improvement of their conductivity, and the enhancement of their stability.104,105 It is possible to build MOF-composites by in situ growth on conductive substrates such as graphene, nanorods, or carbon nanotubes.106,107 The charge transfer from the electrode catalyst is facilitated when a strong interaction between MOFs and substrates occurred and the number of exposed active sites increases.
Noble metal-based MOFs, Fe-, Co-, and Zn-MOFs108,109 have been employed in the electrochemical conversion of CO2 to CO; a Cu-based MOFs has been employed for the reduction of CO2 to C2 and C3 hydrocarbon.110
The use of thin-film MOFs and the tuning of the film thickness are fundamental for the optimization of the mass and charge transport. This approach has been extended to iron porphyrin in the MOF [Zr6O4(OH)4(TCPP-Fe)3], which converts CO2 to CO in DMF and tetrabutylammonium hexafluorophosphate with a TON of 272 in 4 h. The active center is likely an Fe(0). Electrophoretic deposition of Fe-MOF-525 on a fluorine-doped tin oxide glass gave a catalyst able to reduce CO2 and produce CO and H2 in an equal amount.102 A nanosized cobalt-porphyrin MOF thin film Al2(OH)2TCCP-Co showed high selectivity for CO production.111
Zn-based MOFs have been also employed as a catalyst for electrochemical reduction of CO2. The morphology of the MOF influences the current density and the selectivity for the reduction to CH4 (Zn-BTC in ionic liquids electrolytes). The Zn-MOF plays a role in facilitating electron transfer, but it is clear that it is due mainly to a synergistic effect of ionic liquids and MOFs.112 In the absence of the Zn-MOF, the reduction produces mainly CO.113
Uniform films of HKUST-1 were employed as electrocatalysts for selective reduction of CO2 in DMF, Cu+ is also generated during the process.114 A copper rubeanate MOF has been demonstrated to improve the catalytic activity of electrochemical reduction of CO2 as a consequence of its conductivity, nanoporosity, and dispersed reaction sites presence. The reduction product during the potentiostatic electrolysis is mainly HCCOH on the copper rubeanate-MOF electrode.115 HKUST-1 and other three copper-based MOFs have been employed as support on gas diffusion electrodes, high surface areas, accessibilities and exposure of the catalytic centers being favorable for electrocatalytic CO2 reduction.116 Noble metal-based catalysts can be grafted on the electrodes: ReL3(CO)3Cl in highly oriented SURMOF films grown on FTO demonstrated excellent electrocatalytic performance with high Faradic efficiency for the reduction of CO2 to CO.101
MOFs reached great success as catalysts for CO2 conversion through chemical fixation, photocatalysis, and electrocatalysis; we reported here some relationships between the physicochemical properties of MOFs and their catalytic performances. Most of the reported catalytic CO2 reactions are carried out under rough conditions, including alkaline environments in CO2 photoreduction, high temperature in CO2 hydrogenation. Design and synthesis of efficient MOF catalysts able to operate under mild conditions, as low temperature and atmospheric pressure are still a challenge. Accordingly, high CO2 adsorption selectivity of MOF materials enhance the local CO2 concentration at catalytically active sites boosting reaction yields. Ultrahigh porosity, crystallinity, and tunable pore size make MOFs as a perspective material with high CO2 capturing abilities. Specifically, the choice of suitable functional groups in MOF can improve the CO2 uptake, whereas other reactants can enhance the catalytic efficiencies of MOF-based catalysts. Moreover, the tunable structures of MOFs optimized the band gaps and light adsorption for photocatalytic reduction. We have highlighted here that, for example, the presence of NH2 groups in the linker, but also the use of polycyclic aromatic compounds increases the photoresponse under solar-light exposure. Using MOFs in electrochemical reduction achieves the high turnover number with low overpotential and maximizes the mass and charge transport in a well-orientated thin film. We also discussed stability and recyclability under different reaction conditions. The MOF performances have been discussed on the basis of MOFs electronic properties and porosity.
Chu S.: Carbon capture and sequestration. Science 325, 1599 (2009).
Lu A.H. and Hao G.P.: Porous materials for carbon dioxide capture. Annu. Rep. Prog. Chem. A 109, 484 (2013).
Tu W., Zhou Y., and Zou Z.: Photocatalytic conversion of CO2 into renewable hydrocarbon fuels: State-of-the-art accomplishment, challenges, and prospects. Adv. Mater. 26, 4607 (2014).
Qiao J., Liu Y., Hong F., and Zhang J.: A review of catalysts for the electroreduction of carbon dioxide to produce low-carbon fuels. Chem. Soc. Rev. 43, 631 (2014).
Rahmani F., Haghighi M., Estifaee P., and Rahimpour M.R.: A comparative study of two different membranes applied for auto-thermal methanol synthesis process. J. Nat. Gas Sci. Eng. 7, 60 (2012).
Yasuda H., He L.N., Sakakura T., and Hu C.: Efficient synthesis of cyclic carbonate from carbon dioxide catalyzed by polyoxometalate: The remarkable effects of metal substitution. J. Catal. 233, 119 (2005).
Hudson M.R., Queen W.L., Mason J.A., Fickel D.W., Lobo R.F., and Brown C.M.: Unconventional, highly selective CO2 adsorption in zeolite SSZ-13. J. Am. Chem. Soc. 134, 1970 (2012).
Zhang Y., Li B., Williams K., Gao W.Y., and Ma S.: A new microporous carbon material synthesized via thermolysis of a porous aromatic framework embedded with an extra carbon source for low-pressure CO2 uptake. Chem. Commun. 49, 10269 (2013).
Chughtai A.H., Ahmad N., Younus H.A., Laypkov A., and Verpoort F.: Metal-organic frameworks: Versatile heterogeneous catalysts for efficient catalytic organic transformations. Chem. Soc. Rev. 44, 6804 (2015).
Gascon J., Corma A., Kapteijn F., Llabrés I., and Xamena F.X.: Metal organic framework catalysis: Quo vadis? ACS Catal. 4, 361 (2014).
Nguyen P.T.K., Nguyen H.T.D., Nguyen H.N., Trickett C.A., Ton Q.T., Gutiérrez-Puebla E., Monge M.A., Cordova K.E., and Gándara F.: New metal-organic frameworks for chemical fixation of CO2. ACS Appl. Mater. Interfaces 10, 733 (2018).
Chen F., Dong T., Xu T., Li X., and Hu C.: Direct synthesis of cyclic carbonates from olefins and CO2 catalyzed by a MoO2(acac)2-quaternary ammonium salt system. Green Chem. 13, 2518 (2011).
Han Q., He C., Zhao M., Qi B., Niu J., and Duan C.: Engineering chiral polyoxometalate hybrid metal-organic frameworks for asymmetric dihydroxylation of olefins. J. Am. Chem. Soc. 135, 10186 (2013).
Zalomaeva O.V., Chibiryaev A.M., Kovalenko K.A., Kholdeeva O.A., Balzhinimaev B.S., and Fedin V.P.: Cyclic carbonates synthesis from epoxides and CO2 over metal-organic framework Cr-MIL-101. J. Catal. 298, 179 (2013).
Cho H.Y., Yang D.A., Kim J., Jeong S.Y., and Ahn W.S.: CO2 adsorption and catalytic application of Co-MOF-74 synthesized by microwave heating. Catal. Today 185, 35 (2012).
Guillerm V., Weseliński ŁJ, Belmabkhout Y., Cairns A.J., D'Elia V., Wojtas Ł, Adil K., and Eddaoudi M.: Discovery and introduction of a (3,18)-connected net as an ideal blueprint for the design of metal-organic frameworks. Nat. Chem. 6, 673 (2014).
Beyzavi M.H., Klet R.C., Tussupbayev S., Borycz J., Vermeulen N.A., Cramer C.J., Stoddart J.F., Hupp J.T., and Farha O.K.: A hafnium-based metal-organic framework as an efficient and multifunctional catalyst for facile CO2 fixation and regioselective and enantioretentive epoxide activation. J. Am. Chem. Soc. 136, 15861 (2014).
Zou R., Li P.-Z., Zeng Y.-F., Liu J., Zhao R., Duan H., Luo Z., Wang J.-G., Zou R., and Zhao Y.: Bimetallic metal-organic frameworks: Probing the lewis acid site for CO2 conversion. Small 12, 2334 (2016).
Wang S., Yang L., He G., Shi B., Li Y., Wu H., Zhang R., Nunes S., and Jiang Z.: Two-dimensional nanochannel membranes for molecular and ionic separations. Chem. Soc. Rev. 49, 1071 (2020).
Gao W.Y., Chen Y., Niu Y., Williams K., Cash L., Perez P.J., Wojtas L., Cai J., Chen Y.S., and Ma S.: Crystal engineering of an nbo topology metal-organic framework for chemical fixation of CO2 under ambient conditions. Angew. Chem. Int. Ed. 53, 2615 (2014).
Ma D., Li B., Liu K., Zhang X., Zou W., Yang Y., Li G., Shi Z., and Feng S.: Bifunctional MOF heterogeneous catalysts based on the synergy of dual functional sites for efficient conversion of CO2 under mild and co-catalyst free conditions. J. Mater. Chem. A 3, 23136 (2015).
Zhou Z., He C., Xiu J., Yang L., and Duan C.: Metal-organic polymers containing discrete single-walled nanotube as a heterogeneous catalyst for the cycloaddition of carbon dioxide to epoxides. J. Am. Chem. Soc. 137, 15066 (2015).
Gao W.Y., Chen Y., Niu Y., Williams K., Cash L., Perez P.J., Wojtas L., Cai J., Chen Y.S., and Ma S.: Crystal engineering of an nbo topology metal-organic framework for chemical fixation of CO2 under ambient conditions. Angew. Chem. Int. Ed. 53, 2615 (2014).
Kathalikkattil A.C., Roshan R., Tharun J., Babu R., Jeong G.S., Kim D.W., Cho S.J., and Park D.W.: A sustainable protocol for the facile synthesis of zinc-glutamate MOF: An efficient catalyst for room temperature CO2 fixation reactions under wet conditions. Chem. Commun. 52, 280 (2016).
Rachuri Y., Kurisingal J.F., Chitumalla R.K., Vuppala S., Gu Y., Jang J., Choe Y., Suresh E., and Park D.W.: Adenine-based Zn(II)/Cd(II) metal-organic frameworks as efficient heterogeneous catalysts for facile CO2 fixation into cyclic carbonates: A DFT-supported study of the reaction mechanism. Inorg. Chem. 58, 11389 (2019).
Miralda C.M., MacIas E.E., Zhu M., Ratnasamy P., and Carreon M.A.: Zeolitic imidazole framework-8 catalysts in the conversion of CO2 to chloropropene carbonate. ACS Catal. 2, 180 (2012).
Kim Y.J. and Park D.W.: Functionalized IRMOF-3: An efficient heterogeneous catalyst for the cycloaddition of allyl glycidyl ether and CO2. J. Nanosci. Nanotechnol. 13, 2307 (2013).
Song J., Zhang Z., Hu S., Wu T., Jiang T., and Han B.: MOF-5/n-Bu4NBr: An efficient catalyst system for the synthesis of cyclic carbonates from epoxides and CO2 under mild conditions. Green Chem. 11, 1031 (2009).
Zhang L., Yuan S., Feng L., Guo B., Qin J.-S., Xu B., Lollar C., Sun D., and Zhou H.-C.: Pore-environment engineering with multiple metal sites in rare-earth porphyrinic metal-organic frameworks. Angew. Chem. Int. Ed. 57, 5095 (2018).
Ji X.H., Zhu N.N., Ma J.G., and Cheng P.: Conversion of CO2 into cyclic carbonates by a Co(ii) metal-organic framework and the improvement of catalytic activity: Via nanocrystallization. Dalt. Trans. 47, 1768 (2018).
Feng D., Chung W.C., Wei Z., Gu Z.Y., Jiang H.L., Chen Y.P., Darensbourg D.J., and Zhou H.C.: Construction of ultrastable porphyrin Zr metal-organic frameworks through linker elimination. J. Am. Chem. Soc. 135, 17105 (2013).
Gao W.-Y., Chen Y., Niu Y., Williams K., Cash L., Perez P.J., Wojtas L., Cai J., Chen Y.-S., and Ma S.: Crystal engineering of an nbo topology metal-organic framework for chemical fixation of CO2 under ambient conditions. Angew. Chem. Int. Ed. 53, 2615 (2014).
Kleist W., Jutz F., Maciejewski M., and Baiker A.: Mixed-linker metal-organic frameworks as catalysts for the synthesis of propylene carbonate from propylene oxide and CO2. Eur. J. Inorg. Chem. 2009, 3552 (2009).
Lescouet T., Chizallet C., and Farrusseng D.: The origin of the activity of amine-functionalized metal-organic frameworks in the catalytic synthesis of cyclic carbonates from epoxide and CO2. ChemCatChem 4, 1725 (2012).
Kim J., Kim S.N., Jang H.G., Seo G., and Ahn W.S.: CO2 cycloaddition of styrene oxide over MOF catalysts. Appl. Catal. A Gen. 453, 175 (2013).
Beyzavi M.H., Stephenson C.J., Liu Y., Karagiaridi O., Hupp J.T., and Farha O.K.: Metal-organic framework-based catalysts: Chemical fixation of CO2 with epoxides leading to cyclic organic carbonates. Front. Energy Res. 3, 63 (2015).
Vismara R., Tuci G., Mosca N., Domasevitch K.V., Di Nicola C., Pettinari C., Giambastiani G., Galli S., and Rossin A.: Amino-decorated bis(pyrazolate) metal–organic frameworks for carbon dioxide capture and green conversion into cyclic carbonates. Inorg. Chem. Front. 6, 533 (2019).
Müller P., Bucior B., Tuci G., Luconi L., Getzschmann J., Kaskel S., Snurr R.Q., Giambastiani G., and Rossin A.: Computational screening, synthesis and testing of metal-organic frameworks with a bithiazole linker for carbon dioxide capture and its green conversion into cyclic carbonates. Mol. Syst. Des. Eng. 4, 1000 (2019).
Babu R., Kathalikkattil A.C., Roshan R., Tharun J., Kim D.W., and Park D.W.: Dual-porous metal organic framework for room temperature CO2 fixation via cyclic carbonate synthesis. Green Chem. 18, 232 (2015).
Cao C.S., Shi Y., Xu H., and Zhao B.: A multifunctional MOF as a recyclable catalyst for the fixation of CO2 with aziridines or epoxides and as a luminescent probe of Cr(VI). Dalt. Trans. 47, 4545 (2018).
Kumar S., Verma G., Gao W.-Y., Niu Z., Wojtas L., and Ma S.: Anionic metal-organic framework for selective dye removal and CO2 fixation. Eur. J. Inorg. Chem. 2016, 4373 (2016).
Li X.Y., Ma L.N., Liu Y., Hou L., Wang Y.Y., and Zhu Z.: Honeycomb metal-organic framework with lewis acidic and basic bifunctional sites: Selective adsorption and CO2 catalytic fixation. ACS Appl. Mater. Interfaces 10, 10965 (2018).
He H., Sun Q., Gao W., Perman J.A., Sun F., Zhu G., Aguila B., Forrest K., Space B., and Ma S.: A stable metal-organic framework featuring a local buffer environment for carbon dioxide fixation. Angew. Chem. Int. Ed. 57, 4657 (2018).
Ansari S.N., Kumar P., Gupta A.K., Mathur P., and Mobin S.M.: Catalytic CO2 fixation over a robust lactam-functionalized Cu(II) metal organic framework. Inorg. Chem. 58, 9723 (2019).
Liang L., Liu C., Jiang F., Chen Q., Zhang L., Xue H., Jiang H.L., Qian J., Yuan D., and Hong M.: Carbon dioxide capture and conversion by an acid-base resistant metal-organic framework. Nat. Commun. 8, 1 (2017).
Zhou X., Zhang Y., Yang X., Zhao L., and Wang G.: Functionalized IRMOF-3 as efficient heterogeneous catalyst for the synthesis of cyclic carbonates. J. Mol. Catal. A Chem. 361–362, 12 (2012).
Tharun J., Bhin K.M., Roshan R., Kim D.W., Kathalikkattil A.C., Babu R., Ahn H.Y., Won Y.S., and Park D.W.: Ionic liquid tethered post functionalized ZIF-90 framework for the cycloaddition of propylene oxide and CO2. Green Chem. 18, 2479 (2016).
Kaneti Y.V., Dutta S., Hossain M.S.A., Shiddiky M.J.A., Tung K.L., Shieh F.K., Tsung C.K., Wu K.C.W., and Yamauchi Y.: Strategies for improving the functionality of zeolitic imidazolate frameworks: Tailoring nanoarchitectures for functional applications. Adv. Mater. 29, 1700213 (2017).
Bhin K.M., Tharun J., Roshan K.R., Kim D.W., Chung Y., and Park D.W.: Catalytic performance of zeolitic imidazolate framework ZIF-95 for the solventless synthesis of cyclic carbonates from CO2 and epoxides. J. CO2 Util. 17, 112 (2017).
Liang J., Xie Y.Q., Wang X.S., Wang Q., Liu T.T., Huang Y.B., and Cao R.: An imidazolium-functionalized mesoporous cationic metal-organic framework for cooperative CO2 fixation into cyclic carbonate. Chem. Commun. 54, 342 (2018).
Manjolinho F., Arndt M., Gooßen K., and Gooßen L.J.: Catalytic C-H carboxylation of terminal alkynes with carbon dioxide. ACS Catal. 2, 2014 (2012).
Xiong G., Yu B., Dong J., Shi Y., Zhao B., and He L.N.: Cluster-based MOFs with accelerated chemical conversion of CO2 through C-C bond formation. Chem. Commun. 53, 6013 (2017).
Zhang Y., Li B., Krishna R., Wu Z., Ma D., Shi Z., Pham T., Forrest K., Space B., and Ma S.: Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation. Chem. Commun. 51, 2714 (2015).
Li B., Zhang Y., Krishna R., Yao K., Han Y., Wu Z., Ma D., Shi Z., Pham T., Space B., Liu J., Thallapally P.K., Liu J., Chrzanowski M., and Ma S.: Introduction of π-complexation into porous aromatic framework for highly selective adsorption of ethylene over ethane. J. Am. Chem. Soc. 136, 8654 (2014).
Zhou Z., He C., Yang L., Wang Y., Liu T., and Duan C.: Alkyne activation by a porous silver coordination polymer for heterogeneous catalysis of carbon dioxide cycloaddition. ACS Catal. 7, 2248 (2017).
Zhang G., Yang H., and Fei H.: Unusual missing linkers in an organosulfonate-based primitive-cubic (pcu)-type metal-organic framework for CO2 capture and conversion under ambient conditions. ACS Catal. 8, 2519 (2018).
Liu X.H., Ma J.G., Niu Z., Yang G.M., and Cheng P.: An efficient nanoscale heterogeneous catalyst for the capture and conversion of carbon dioxide at ambient pressure. Angew. Chem. Int. Ed. 54, 988 (2015).
Molla R.A., Ghosh K., Banerjee B., Iqubal M.A., Kundu S.K., Islam S.M., and Bhaumik A.: Silver nanoparticles embedded over porous metal organic frameworks for carbon dioxide fixation via carboxylation of terminal alkynes at ambient pressure. J. Colloid Interface Sci. 477, 220 (2016).
Gao W.Y., Wu H., Leng K., Sun Y., and Ma S.: Inserting CO2 into Aryl C-H bonds of metal-organic frameworks: CO2 Utilization for direct heterogeneous C-H activation. Angew. Chem. Int. Ed. 55, 5472 (2016).
McDonald T.M., Mason J.A., Kong X., Bloch E.D., Gygi D., Dani A., Crocellà V., Giordanino F., Odoh S.O., Drisdell W.S., Vlaisavljevich B., Dzubak A.L., Poloni R., Schnell S.K., Planas N., Lee K., Pascal T., Wan L.F., Prendergast D., Neaton J. B., Smit B., Kortright Gagliardi, L. Bordiga S. Reimer J.A., Long J.R.: Cooperative insertion of CO2 in diamine-appended metal-organic frameworks. Nature 519, 303 (2015).
Zhao D., Liu X.-H., Zhu C., Kang Y.-S., Wang P., Shi Z., Lu Y., and Sun W.-Y.: Efficient and reusable metal-organic framework catalysts for carboxylative cyclization of propargylamines with carbon dioxide. ChemCatChem 9, 4598 (2017).
Li W., Wang H., Jiang X., Zhu J., Liu Z., Guo X., and Song C.: A short review of recent advances in CO2 hydrogenation to hydrocarbons over heterogeneous catalysts. RSC Adv. 8, 7651 (2018).
Younas M., Loong Kong L., Bashir M.J.K., Nadeem H., Shehzad A., and Sethupathi S.: Recent advancements, fundamental challenges, and opportunities in catalytic methanation of CO2. Energy Fuels 30, 8815 (2016).
Zhen W., Li B., Lu G., and Ma J.: Enhancing catalytic activity and stability for CO2 methanation on Ni@MOF-5 via control of active species dispersion. Chem. Commun. 51, 1728 (2015).
Li W., Zhang A., Jiang X., Chen C., Liu Z., Song C., and Guo X.: Low temperature CO2 methanation: ZIF-67-derived Co-based porous carbon catalysts with controlled crystal morphology and size. ACS Sustain. Chem. Eng. 5, 7824 (2017).
Zhan G. and Zeng H.C.: ZIF-67-derived nanoreactors for controlling product selectivity in CO2 hydrogenation. ACS Catal. 7, 7509 (2017).
Lippi R., Howard S.C., Barron H., Easton C.D., Madsen I.C., Waddington L.J., Vogt C., Hill M.R., Sumby C.J., Doonan C.J., and Kennedy D.F.: Highly active catalyst for CO2 methanation derived from a metal organic framework template. J. Mater. Chem. A 5, 12990 (2017).
Zhang T., Manna K., and Lin W.: Metal-organic frameworks stabilize solution-inaccessible cobalt catalysts for highly efficient broad-scope organic transformations. J. Am. Chem. Soc. 138, 3241 (2016).
Yin Y., Hu B., Li X., Zhou X., Hong X., and Liu G.: Pd@zeolitic imidazolate framework-8 derived PdZn alloy catalysts for efficient hydrogenation of CO2 to methanol. Appl. Catal. B Environ. 234, 143 (2018).
Rungtaweevoranit B., Baek J., Araujo J.R., Archanjo B.S., Choi K.M., Yaghi O.M., and Somorjai G.A.: Copper nanocrystals encapsulated in Zr-based metal-organic frameworks for highly selective CO2 hydrogenation to methanol. Nano Lett. 16, 7645 (2016).
An B., Zhang J., Cheng K., Ji P., Wang C., and Lin W.: Confinement of ultrasmall Cu/ZnOx nanoparticles in metal-organic frameworks for selective methanol synthesis from catalytic hydrogenation of CO2. J. Am. Chem. Soc. 139, 3834 (2017).
An B., Li Z., Song Y., Zhang J., Zeng L., Wang C., and Lin W.: Cooperative copper centres in a metal–organic framework for selective conversion of CO2 to ethanol. Nat. Catal. 2, 709 (2019).
Liu J., Sun Y., Jiang X., Zhang A., Song C., and Guo X.: Pyrolyzing ZIF-8 to N-doped porous carbon facilitated by iron and potassium for CO2 hydrogenation to value-added hydrocarbons. J. CO2 Util. 25, 120 (2018).
Liu J., Zhang A., Liu M., Hu S., Ding F., Song C., and Guo X.: Fe-MOF-derived highly active catalysts for carbon dioxide hydrogenation to valuable hydrocarbons. J. CO2 Util. 21, 100 (2017).
An B., Cheng K., Wang C., Wang Y., and Lin W.: Pyrolysis of metal-organic frameworks to Fe3O4@Fe5C2 core-shell nanoparticles for fischer-tropsch synthesis. ACS Catal. 6, 3610 (2016).
Meng W., Chen W., Zhao L., Huan G.Y., Zhu M., Huang Y., Fu Y., Geng F., Yu J., Chen X., and Zhi C.: Porous Fe3O4/carbon composite electrode material prepared from metal-organic framework template and effect of temperature on its capacitance. Nano Energy 8, 133 (2014).
Li Z., Rayder T.M., Luo L., Byers J.A., and Tsung C.K.: Aperture-opening encapsulation of a transition metal catalyst in a metal-organic framework for CO2 hydrogenation. J. Am. Chem. Soc. 140, 8082 (2018).
Xu W., Zhang X., Dong M., Zhao J., and Di L.: Plasma-assisted Ru/Zr-MOF catalyst for hydrogenation of CO2 to methane. Plasma Sci. Technol. 21, 044004 (2019).
Wang C., Xie Z., Dekrafft K.E., and Lin W.: Doping metal-organic frameworks for water oxidation, carbon dioxide reduction, and organic photocatalysis. J. Am. Chem. Soc. 133, 13445 (2011).
Alvaro M., Carbonell E., Ferrer B., Llabrés I., Xamena F.X., and Garcia H.: Semiconductor behavior of a metal-organic framework (MOF). Chemistry 13, 5106 (2007).
Lee Y., Kim S., Kang J.K., and Cohen S.M.: Photocatalytic CO2 reduction by a mixed metal (Zr/Ti), mixed ligand metal-organic framework under visible light irradiation. Chem. Commun. 51, 5735 (2015).
Nasalevich M.A., Hendon C.H., Santaclara J.G., Svane K., Van Der Linden B., Veber S.L., Fedin M.V., Houtepen A.J., Van Der Veen M.A., Kapteijn F., Walsh A., and Gascon J.: Electronic origins of photocatalytic activity in d0 metal organic frameworks. Sci. Rep. 6, 23676 (2016).
Windle C.D., George M.W., Perutz R.N., Summers P.A., Sun X.Z., and Whitwood A.C.: Comparison of rhenium-porphyrin dyads for CO2 photoreduction: Photocatalytic studies and charge separation dynamics studied by time-resolved IR spectroscopy. Chem. Sci. 6, 6847 (2015).
Fu Y., Sun D., Chen Y., Huang R., Ding Z., Fu X., and Li Z.: An amine-functionalized titanium metal-organic framework photocatalyst with visible-light-induced activity for CO2 reduction. Angew. Chem. Int. Ed. 51, 3364 (2012).
Cavka J.H., Jakobsen S., Olsbye U., Guillou N., Lamberti C., Bordiga S., and Lillerud K.P.: A new zirconium inorganic building brick forming metal organic frameworks with exceptional stability. J. Am. Chem. Soc. 130, 13850 (2008).
Wang Y., Huang N.Y., Shen J.Q., Liao P.Q., Chen X.M., and Zhang J.P.: Hydroxide ligands cooperate with catalytic centers in metal-organic frameworks for efficient photocatalytic CO2 reduction. J. Am. Chem. Soc. 140, 38 (2018).
Kajiwara T., Fujii M., Tsujimoto M., Kobayashi K., Higuchi M., Tanaka K., and Kitagawa S.: Photochemical reduction of low concentrations of CO2 in a porous coordination polymer with a ruthenium(II)-CO complex. Angew. Chem. Int. Ed. 55, 2697 (2016).
Wang D., Huang R., Liu W., Sun D., and Li Z.: Fe-based MOFs for photocatalytic CO2 reduction: Role of coordination unsaturated sites and dual excitation pathways. ACS Catal. 4, 4254 (2014).
Dao X.Y., Guo J.H., Wei Y.P., Guo F., Liu Y., and Sun W.Y.: Solvent-free photoreduction of CO2 to CO catalyzed by Fe-MOFs with superior selectivity. Inorg. Chem. 58, 8517 (2019).
Xu H.Q., Hu J., Wang D., Li Z., Zhang Q., Luo Y., Yu S.H., and Jiang H.L.: Visible-light photoreduction of CO2 in a metal-organic framework: Boosting electron-hole separation via electron trap states. J. Am. Chem. Soc. 137, 13440 (2015).
Chen D., Xing H., Wang C., and Su Z.: Highly efficient visible-light-driven CO2 reduction to formate by a new anthracene-based zirconium MOF via dual catalytic routes. J. Mater. Chem. A 4, 2657 (2016).
Wu L.Y., Mu Y.F., Guo X.X., Zhang W., Zhang Z.M., Zhang M., and Lu T.B.: Encapsulating perovskite quantum dots in iron-based Metal–Organic Frameworks (MOFs) for efficient photocatalytic CO2 reduction. Angew. Chem. Int. Ed. 58, 9491 (2019).
Zhu W., Zhang C., Li Q., Xiong L., Chen R., Wan X., Wang Z., Chen W., Deng Z., and Peng Y.: Selective reduction of CO2 by conductive MOF nanosheets as an efficient co-catalyst under visible light illumination. Appl. Catal. B Environ. 238, 339 (2018).
Al-Omari A.A., Yamani Z.H., and Nguyen H.L.: Electrocatalytic CO2 reduction: From homogeneous catalysts to heterogeneous-based reticular chemistry. Molecules 23, 2835 (2018).
Huang Z., Dong P., Zhang Y., Nie X., Wang X., and Zhang X.: A ZIF-8 decorated TiO2 grid-like film with high CO2 adsorption for CO2 photoreduction. J. CO2 Util. 24, 369 (2018).
Liu Q., Low Z.X., Li L., Razmjou A., Wang K., Yao J., and Wang H.: ZIF-8/Zn2GeO4 nanorods with an enhanced CO2 adsorption property in an aqueous medium for photocatalytic synthesis of liquid fuel. J. Mater. Chem. A 1, 11563 (2013).
Habisreutinger S.N., Schmidt-Mende L., and Stolarczyk J.K.: Photocatalytic reduction of CO2 on TiO2 and other semiconductors. Angew. Chem. Int. Ed. 52, 7372 (2013).
Sun D., Liu W., Fu Y., Fang Z., Sun F., Fu X., Zhang Y., and Li Z.: Noble metals can have different effects on photocatalysis over metal-organic frameworks (MOFs): A case study on M/NH2-MIL-125(Ti) (M = Pt and Au). Chem. A Eur. J. 20, 4780 (2014).
Wang S., Lin J., and Wang X.: Semiconductor-redox catalysis promoted by metal-organic frameworks for CO2 reduction. Phys. Chem. Chem. Phys. 16, 14656 (2014).
Shi L., Wang T., Zhang H., Chang K., and Ye J.: Electrostatic self-assembly of nanosized carbon nitride nanosheet onto a zirconium metal-organic framework for enhanced photocatalytic CO2 reduction. Adv. Funct. Mater. 25, 5360 (2015).
Ye L., Liu J., Gao Y., Gong C., Addicoat M., Heine T., Wöll C., and Sun L.: Highly oriented MOF thin film-based electrocatalytic device for the reduction of CO2 to CO exhibiting high faradaic efficiency. J. Mater. Chem. A 4, 15320 (2016).
Hod I., Sampson M.D., Deria P., Kubiak C.P., Farha O.K., and Hupp J.T.: Fe-porphyrin-based metal-organic framework films as high-surface concentration, heterogeneous catalysts for electrochemical reduction of CO2. ACS Catal. 5, 6302 (2015).
Shao P., Yi L., Chen S., Zhou T., and Zhang J.: Metal-organic frameworks for electrochemical reduction of carbon dioxide: The role of metal centers. J. Energy Chem. 40, 156 (2020).
Zhang H., Li J., Tan Q., Lu L., Wang Z., and Wu G.: Metal–organic frameworks and their derived materials as electrocatalysts and photocatalysts for CO2 reduction: Progress, challenges, and perspectives. Chem. A Eur. J. 24, 18137 (2018).
Lei Z., Xue Y., Chen W., Qiu W., Zhang Y., Horike S., and Tang L.: MOFs-based heterogeneous catalysts: New opportunities for energy-related CO2 conversion. Adv. Energy Mater. 8, 1801587 (2018).
Zhang X., Wu Z., Zhang X., Li L., Li Y., Xu H., Li X., Yu X., Zhang Z., Liang Y., and Wang H.: Highly selective and active CO2 reduction electrocatalysts based on cobalt phthalocyanine/carbon nanotube hybrid structures. Nat. Commun. 8, 1 (2017).
Qiu Y.L., Zhong H.X., Zhang T.T., Xu W.B., Su P.P., Li X.F., and Zhang H.M.: Selective electrochemical reduction of carbon dioxide using Cu based metal organic framework for CO2 capture. ACS Appl. Mater. Interfaces 10, 2480 (2018).
Jiang X., Wu H., Chang S., Si R., Miao S., Huang W., Li Y., Wang G., and Bao X.: Boosting CO2 electroreduction over layered zeolitic imidazolate frameworks decorated with Ag2O nanoparticles. J. Mater. Chem. A 5, 19371 (2017).
Huan T.N., Ranjbar N., Rousse G., Sougrati M., Zitolo A., Mougel V., Jaouen F., and Fontecave M.: Electrochemical reduction of CO2 catalyzed by Fe-N-C materials: A structure-selectivity study. ACS Catal. 7, 1520 (2017).
Nam D.H., Bushuyev O.S., Li J., De Luna P., Seifitokaldani A., Dinh C.T., De García Arquer F.P., Wang Y., Liang Z., Proppe A.H., Tan C.S., Todorović P., Shekhah O., Gabardo C.M., Jo J.W., Choi J., Choi M.J., Baek S.W., et al.: Metal-organic frameworks mediate Cu coordination for selective CO2 electroreduction. J. Am. Chem. Soc. 140, 11378 (2018).
Kornienko N., Zhao Y., Kley C.S., Zhu C., Kim D., Lin S., Chang C.J., Yaghi O.M., and Yang P.: Metal-organic frameworks for electrocatalytic reduction of carbon dioxide. J. Am. Chem. Soc. 137, 14129 (2015).
Kang X., Zhu Q., Sun X., Hu J., Zhang J., Liu Z., and Han B.: Highly efficient electrochemical reduction of CO2 to CH4 in an ionic liquid using a metal-organic framework cathode. Chem. Sci. 7, 266 (2016).
Rosen B.A., Haan J.L., Mukherjee P., Braunschweig B., Zhu W., Salehi-Khojin A., Dlott D.D., and Masel R.I.: In situ spectroscopic examination of a low overpotential pathway for carbon dioxide conversion to carbon monoxide. J. Phys. Chem. C 116, 15307 (2012).
Senthil Kumar R., Senthil Kumar S., and Anbu Kulandainathan M.: Highly selective electrochemical reduction of carbon dioxide using Cu based metal organic framework as an electrocatalyst. Electrochem. Commun. 25, 70 (2012).
Hinogami R., Yotsuhashi S., Deguchi M., Zenitani Y., Hashiba H., and Yamada Y.: Electrochemical reduction of carbon dioxide using a copper rubeanate metal organic framework. ECS Electrochem. Lett. 1, H17 (2012).
Albo J., Vallejo D., Beobide G., Castillo O., Castaño P., and Irabien A.: Copper-based metal–organic porous materials for CO2 electrocatalytic reduction to alcohols. ChemSusChem 10, 1100 (2017).
Carbon Capture and Utilization
Fluorine-doped tin oxide
Fischer Tropsch Catalysis
Cyclic organic carbonates
Surface-Anchored Metal–Organic Frameworks
Total turnover number
Zeolitic imidazolate framework
[Co(μ3-L)(H2O)]⋅0.5H2O (L = thiazolidine 2,4-dicarboxylate)
[Zr6O4(OH)4(L)6]⋅6DMF (L = 4,40-(anthracene- 9,10-diylbis(ethyne-2,1-diyl))dibenzoate)
About this article
Cite this article
Pettinari, C., Tombesi, A. Metal–organic frameworks for chemical conversion of carbon dioxide. MRS Energy & Sustainability 7, 31 (2020). https://doi.org/10.1557/mre.2020.35
- carbon dioxide
- metal–organic framework (MOF)