Acrylic acid hydrodeoxygenation reaction mechanism over molybdenum carbide studied by DFT calculations

  • Ricardo R. OliveiraEmail author
  • Alexandre B. Rocha
Original Paper


Platinum- and palladium-based catalysts are commonly used in hydrogenation reactions, but they present a great disadvantage of being quite expensive. In most cases, they can be substituted by cheaper alternative catalysts formed by transition metal carbides, such as molybdenum carbide (Mo2C). Among the reactions that can be catalyzed by Mo2C, hydrodeoxygenation (HDO) presents a great technological interest, especially in biofuel production. Nonetheless, the selectivity of carbides in HDO reactions of fatty acids is not well understood yet. In the present work, the reaction mechanism of the acrylic acid HDO over Mo2C, a fatty acid model molecule, was studied by density functional theory (DFT), with Perdew-Burke-Ernzerhof (PBE) functional and periodic boundary conditions. A global mechanism is proposed, divided in four steps, from acrylic acid to propane. In the first reaction step, decomposition by C–OH bond cleavage, with 24 kcal mol− 1 of activation energy, dominates over C=C and C=O hydrogenation. This result is in line with the absence of propanoic acid among the products and the formation of acrolein, as shown in an experimental work previously published. The proposed global mechanism is in fair agreement with the experimental findings. The main product is propane, which has the same number of carbon atoms of the reactant. This mechanism can be viewed as a model for HDO of any fatty acid catalyzed by Mo2C, since acrylic acid has the minimal structural features of fatty acids, i.e., a carboxyl group and a C=C double bond.

Graphical Abstract

HDO over Mo2C provides a product with same carbon atoms number of the reactant.


DFT HDO Molybdenum carbide Fatty acid 



The authors also acknowledge the Laboratório Nacional de Computação Científica (LNCC) for computational support of SDumont supercomputer under project ID 25972.

Funding information

The authors acknowledge Conselho Nacional de Desenvolvimento e Pesquisa (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) for financial support.

Supplementary material

894_2019_4186_MOESM1_ESM.pdf (833 kb)
(PDF 833 KB)


  1. 1.
    Oyama S (1992) Preparation and catalytic properties of transition metal carbides and nitrides. Catal Today 15(2):179–200. CrossRefGoogle Scholar
  2. 2.
    Sullivan MM, Bhan A (2016) Acetone hydrodeoxygenation over bifunctional metallic–acidic molybdenum carbide catalysts. ACS Catal 6(2):1145–1152. CrossRefGoogle Scholar
  3. 3.
    Rocha A, Rocha A, da Silva VT (2010) Benzene adsorption on Mo2C: a theoretical and experimental study. Appl Catal A Gen 379(1-2):54–60. CrossRefGoogle Scholar
  4. 4.
    Flaherty DW, Berglund SP, Mullins CB (2010) Selective decomposition of formic acid on molybdenum carbide: a new reaction pathway. J Catal 269(1):33–43. CrossRefGoogle Scholar
  5. 5.
    Sullivan MM, Chen CJ, Bhan A (2016) Catalytic deoxygenation on transition metal carbide catalysts. Cat Sci Technol 6(3):602–616. CrossRefGoogle Scholar
  6. 6.
    Xiong K, Yu W, Vlachos DG, Chen JG (2015) Reaction pathways of biomass-derived oxygenates over metals and carbides: from model surfaces to supported catalysts. ChemCatChem 7(9):1402–1421. CrossRefGoogle Scholar
  7. 7.
    Sousa L, Zotin J, Teixeira da Silva V (2012) Hydrotreatment of sunflower oil using supported molybdenum carbide. Appl Catal A Gen 449:105–111. CrossRefGoogle Scholar
  8. 8.
    Han J, Duan J, Chen P, Lou H, Zheng X, Hong H (2012) Carbon-supported molybdenum carbide catalysts for the conversion of vegetable oils. ChemSusChem 5(4):727–733. CrossRefPubMedGoogle Scholar
  9. 9.
    Boullosa-Eiras S, Lødeng R, Bergem H, Stöcker M, Hannevold L, Blekkan EA (2014) Catalytic hydrodeoxygenation (HDO) of phenol over supported molybdenum carbide, nitride, phosphide and oxide catalysts. Catal Today 223:44–53. CrossRefGoogle Scholar
  10. 10.
    Lee WS, Wang Z, Zheng W, Vlachos DG, Bhan A (2014) Vapor phase hydrodeoxygenation of furfural to 2-methylfuran on molybdenum carbide catalysts. Cat Sci Technol 4(8):2340. CrossRefGoogle Scholar
  11. 11.
    Lee WS, Wang Z, Wu RJ, Bhan A (2014) Selective vapor-phase hydrodeoxygenation of anisole to benzene on molybdenum carbide catalysts. J Catal 319:44–53. CrossRefGoogle Scholar
  12. 12.
    He L, Qin Y, Lou H, Chen P (2015) Highly dispersed molybdenum carbide nanoparticles supported on activated carbon as an efficient catalyst for the hydrodeoxygenation of vanillin. RSC Adv 5(54):43,141–43,147. CrossRefGoogle Scholar
  13. 13.
    Lu M, Lu F, Zhu J, Li M, Zhu J, Shan Y (2015) Hydrodeoxygenation of methyl stearate as a model compound over Mo2C supported on mesoporous carbon. React Kinet Mech Catal 115 (1):251–262. CrossRefGoogle Scholar
  14. 14.
    Shi Y, Yang Y, Li Y W, Jiao H (2016) Mechanisms of Mo2C(101)-catalyzed furfural selective hydrodeoxygenation to 2-methylfuran from computation. ACS Catal. 6(10):6790–6803. CrossRefGoogle Scholar
  15. 15.
    Qi KZ, Wang GC, Zheng WJ (2013) A first-principles study of CO hydrogenation into methane on molybdenum carbides catalysts. Surf Sci 614:53–63. CrossRefGoogle Scholar
  16. 16.
    Engelhardt J, Lyu P, Nachtigall P, Schüth F, García ÁM (2017) The influence of water on the performance of molybdenum carbide catalysts in hydrodeoxygenation reactions: a combined theoretical and experimental study. ChemCatChem 9(11):1985–1991. CrossRefGoogle Scholar
  17. 17.
    Chen CJ, Bhan A (2017) Mo2C modification by CO2, H2O, and O2: effects of oxygen content and oxygen source on rates and selectivity of m-Cresol hydrodeoxygenation. ACS Catal 7 (2):1113–1122. CrossRefGoogle Scholar
  18. 18.
    Zacharopoulou V, Vasiliadou ES, Lemonidou AA (2018) Exploring the reaction pathways of bioglycerol hydrodeoxygenation to propene over molybdena-based catalysts. ChemSusChem 11(1):264–275. CrossRefPubMedGoogle Scholar
  19. 19.
    Qi KZ, Wang GC, Zheng WJ (2013) Structure-sensitivity of ethane hydrogenolysis over molybdenum carbides: a density functional theory study. Appl Surf Sci 276:369–376. CrossRefGoogle Scholar
  20. 20.
    Luo Q, Wang T, Walther G, Beller M, Jiao H (2014) Molybdenum carbide catalysed hydrogen production from formic acid – a density functional theory study. J Power Sources 246:548–555. CrossRefGoogle Scholar
  21. 21.
    Liu X, Salahub DR (2015) Molybdenum carbide nanocatalysts at work in the in situ environment: a density functional tight-binding and quantum mechanical/molecular mechanical study. J Am Chem Soc 137(12):4249–4259. CrossRefPubMedGoogle Scholar
  22. 22.
    Schaidle JA, Blackburn J, Farberow CA, Nash C, Steirer KX, Clark J, Robichaud DJ, Ruddy DA (2016) Experimental and computational investigation of acetic acid deoxygenation over oxophilic molybdenum carbide: surface chemistry and active site identity. ACS Catal 6(2):1181–1197. CrossRefGoogle Scholar
  23. 23.
    Shi Y, Yang Y, Li YW, Jiao H (2016) Theoretical study about Mo2C(101)-catalyzed hydrodeoxygenation of butyric acid to butane for biomass conversion. Cat Sci Technol 6(13):4923–4936. CrossRefGoogle Scholar
  24. 24.
    Kim SK, Kim J, Lee SC (2017) Surface-termination dependence of propanoic acid deoxygenation on Mo2C. Catal Commun 99(February):61–65. CrossRefGoogle Scholar
  25. 25.
    Rocha AS, Souza LA, Oliveira RR, Rocha AB, Teixeira da Silva V (2017) Hydrodeoxygenation of acrylic acid using Mo2C/Al2 O 3. Appl Catal A Gen 531:69–78. CrossRefGoogle Scholar
  26. 26.
    Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77(18):3865–3868. CrossRefPubMedGoogle Scholar
  27. 27.
    Blöchl PE (1994) Projector augmented-wave method. Phys Rev B 50(24):17,953–17,979. CrossRefGoogle Scholar
  28. 28.
    Monkhorst HJ, Pack JD (1976) Special points for Brillouin-zone integrations. Phys Rev B 13(12):5188–5192. arXiv:1011.1669v3 CrossRefGoogle Scholar
  29. 29.
    Methfessel M, Paxton AT (1989) High-precision sampling for Brillouin-zone integration in metals. Phys Rev B 40(6):3616–3621. CrossRefGoogle Scholar
  30. 30.
    Kresse G, Furthmüller J (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 54(16):11,169–11,186. 0927-0256(96)00008CrossRefGoogle Scholar
  31. 31.
    Loffreda D, Jugnet Y, Delbecq F, Bertolini JC, Sautet P (2004) Coverage dependent adsorption of acrolein on pt(111) from a combination of first principle theory and HREELS study. J Phys Chem B 108(26):9085–9093. CrossRefGoogle Scholar
  32. 32.
    Marinelli T, Nabuurs S, Ponec V (1995) Activity and selectivity in the reactions of substituted α, β-unsaturated aldehydes. J Catal 151(2):431–438. CrossRefGoogle Scholar
  33. 33.
    Loffreda D, Delbecq F, Vigné F, Sautet P (2005) Catalytic hydrogenation of unsaturated aldehydes on pt(111): understanding the selectivity from first-principles calculations. Angew Chem Int Ed 44(33):5279–5282. CrossRefGoogle Scholar
  34. 34.
    Loffreda D, Delbecq F, Vigné F, Sautet P (2006) Chemo regioselectivity in heterogeneous catalysis: competitive routes for C=O and C=C hydrogenations from a theoretical approach. J Am Chem Soc 128(4):1316–1323. CrossRefPubMedGoogle Scholar
  35. 35.
    Oliveira RR, Rocha AS, Teixeira Da Silva V, Rocha AB (2014) Investigation of hydrogen occlusion by molybdenum carbide. Appl Catal A Gen 469:139–145. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Instituto de QuímicaUFRJ - Universidade Federal do Rio de JaneiroRio de JaneiroBrazil

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