Effect of Coverage on Catalytic Selectivity and Activity on Metallic and Alloy Catalysts; Vinyl Acetate Monomer Synthesis

Original Paper

Abstract

The repulsive lateral interactions that occur at the high coverages present on catalysts under reaction conditions are likely to exert a significant influence on the reaction energetics. The effect of such lateral interactions are explored for the synthesis of vinyl acetate monomer (VAM) on Pd(111) and Au/Pd(111) alloy model single-crystal catalysts, where the reaction kinetics are monitored by reflection–absorption infrared spectroscopy (RAIRS). It is shown by comparing the reactivity of ethylene and its deuterated isotopomers, and by trapping reaction intermediates, that VAM is formed on Pd(111) by a mechanism first proposed by Samanos, where the reaction is initiated by coupling between ethylene and adsorbed acetate species to form an acetoxyethyl intermediate, followed by a rate-limiting β-hydride elimination step to produce VAM. The reaction comprises two sequential steps; a bond-forming reaction, followed by a bond-breaking step. Repulsive lateral interactions are expected to facilitate bond-forming reactions that reduce the total coverage, but inhibit bond-breaking steps, so that VAM formation provides an ideal reaction to explore these effects. Density functional theory (DFT) calculations confirm the proposed coverage effects and yield energy barriers for the reaction of ethylene with acetate-saturated Pd(111) surfaces that are in excellent agreement with experiment. It is also found that bond-breaking in VAM decomposition is inhibited on a crowded Pd(111) surface, indicating that high adsorbate coverages influence both reactivity and selectivity. VAM formation is also explored on Au/Pd(111) alloys. The catalytic activity of alloys is conventionally discussed by invoking ensemble (geometric) and electronic (ligand) effects. However, the acetate coverage also decreases with increasing gold content of the Au/Pd(111) alloy, thereby decreasing the repulsive lateral interactions. The coverage effects on alloys are found to be as large as the ensemble + electronic effects and induce a change in the rate-limiting step for VAM formation from β-hydride elimination to the ethylene-acetate coupling step.

Keywords

Infrared absorption spectroscopy Palladium Palladium–gold alloy Vinyl acetate monomer Vinyl acetate synthesis Coverage effects 

Notes

Acknowledgements

We gratefully acknowledge the support of this work by the National Science Foundation, under Grant No. CHE-1109377.

References

  1. 1.
    Kesmodel LL, Dubois LH, Somorjai GA (1978) Dynamical LEED study of C2H2 and C2H4 chemisorption on Pt(111): evidence for the ethylidyne group. Chem Phys Letts 56(2):267–271CrossRefGoogle Scholar
  2. 2.
    Kesmodel LL, Dubois LH, Somorjai GA (1979) LEED analysis of acetylene and ethylene chemisorption on the Pt(111) surface: evidence for ethylidyne formation. J Chem Phys 70(5):2180–2188CrossRefGoogle Scholar
  3. 3.
    Skinner P, Howard MW, Oxton IA, Kettle SFA, Powell DB, Sheppard N (1981) Vibrational spectra and the force field of ethylidyne tricobalt nonacarbonyl: analogies with spectra from the chemisorption of ethylene upon the Pt (111) crystal face. J Chem Soc Farad T 2 77(7):1203–1215CrossRefGoogle Scholar
  4. 4.
    Kesmodel LL, Gates JA (1981) Ethylene adsorption and reaction on Pd(111): an angle-dependent EELS analysis. Surf Sci 111(3):L747-L754CrossRefGoogle Scholar
  5. 5.
    Gates JA, Kesmodel LL (1983) Thermal evolution of acetylene and ethylene on Pd(111). Surf Sci 124(1):68–86CrossRefGoogle Scholar
  6. 6.
    Koestner RJ, Van Hove MA, Somorjai GA (1983) Molecular structure of hydrocarbon monolayers on metal surfaces. J Phys Chem 87(2):203–213CrossRefGoogle Scholar
  7. 7.
    Cremer PS, Su X, Shen YR, Somorjai GA (1996) Ethylene hydrogenation on Pt(111) monitored in situ at high pressures using sum frequency generation. J Am Chem Soc 118(12):2942–2949CrossRefGoogle Scholar
  8. 8.
    Zaera F, Somorjai GA (1984) Hydrogenation of ethylene over platinum (111) single-crystal surfaces. J Am Chem Soc 106(8):2288–2293CrossRefGoogle Scholar
  9. 9.
    Moskaleva LV, Chen Z-X, Aleksandrov HA, Mohammed AB, Sun Q, Rösch N (2009) Ethylene conversion to ethylidyne over Pd(111): revisiting the mechanism with first-principles calculations. J Phys Chem C 113(6):2512–2520CrossRefGoogle Scholar
  10. 10.
    Zaera F (2017) The surface chemistry of metal-based hydrogenation catalysis. ACS Catal 7(8):4947–4967CrossRefGoogle Scholar
  11. 11.
    Dostert K-H, O’Brien CP, Ivars-Barceló F, Schauermann S, Freund H-J (2015) Spectators control selectivity in surface chemistry: acrolein partial hydrogenation over Pd. J Am Chem Soc 137(42):13496–13502CrossRefGoogle Scholar
  12. 12.
    Kumar G, Lien C-H, Janik MJ, Medlin JW (2016) Catalyst site selection via control over noncovalent interactions in self-assembled monolayers. ACS Catal 6(8):5086–5094CrossRefGoogle Scholar
  13. 13.
    Lien C-H, Medlin JW (2016) Control of Pd catalyst selectivity with mixed thiolate monolayers. J Catal 339:38–46CrossRefGoogle Scholar
  14. 14.
    Bradshaw AM, Scheffler M (1979) Lateral interactions in adsorbed layers. J Vac Sci Technol 16(2):447–454CrossRefGoogle Scholar
  15. 15.
    Calaza F, Stacchiola D, Neurock M, Tysoe WT (2010) Coverage effects on the palladium-catalyzed synthesis of vinyl acetate: comparison between theory and experiment. J Am Chem Soc 132(7):2202–2207CrossRefGoogle Scholar
  16. 16.
    Evans MG, Polanyi M (1938) Inertia and driving force of chemical reactions. T Farad Soc 34:11–24CrossRefGoogle Scholar
  17. 17.
    Logadottir A, Rod TH, Nørskov JK, Hammer B, Dahl S, Jacobsen CJH (2001) The Brønsted–Evans–Polanyi relation and the volcano plot for ammonia synthesis over transition metal catalysts. J Catal 197(2):229–231CrossRefGoogle Scholar
  18. 18.
    Bligaard T, Nørskov JK, Dahl S, Matthiesen J, Christensen CH, Sehested J (2004) The Brønsted–Evans–Polanyi relation and the volcano curve in heterogeneous catalysis. J Catal 224(1):206–217CrossRefGoogle Scholar
  19. 19.
    Santen RAV, Neurock M, Shetty SG (2009) Reactivity Theory of transition-metal surfaces: a Brønsted–Evans–Polanyi linear activation energy–free-energy analysis. Chem Rev 110(4):2005–2048CrossRefGoogle Scholar
  20. 20.
    Loffreda D, Delbecq F, Vigné F, Sautet P (2009) Fast Prediction of selectivity in heterogeneous catalysis from extended Brønsted–Evans–Polanyi relations: a theoretical insight. Angew Chem 48(47):8978–8980CrossRefGoogle Scholar
  21. 21.
    Santen RAV, Neurock M (2006) Molecular heterogeneous catalysis: a conceptual and computational approach. Wiley-VCH, WeinheimCrossRefGoogle Scholar
  22. 22.
    Pallassana V, Neurock M (2000) Electronic factors governing ethylene hydrogenation and dehydrogenation activity of pseudomorphic PdML/Re(0001), PdML/Ru(0001), Pd(111), and PdML/Au(111) surfaces. J Catal 191(2):301–317CrossRefGoogle Scholar
  23. 23.
    Colling PM, Johnson LR, Nicolau I (1996) Palladium-gold catalyst for vinyl acetate production. United States Patent, US5693586 AGoogle Scholar
  24. 24.
    Horning L, Wunder F, Quadflieg T (1967) Process for preparing vinyl acetates, United States Patent, US20130131261 A1Google Scholar
  25. 25.
    Chen M, Kumar D, Yi C-W, Goodman DW (2005) The promotional effect of gold in catalysis by palladium-gold. Science 310(5746):291–293CrossRefGoogle Scholar
  26. 26.
    Stacchiola D, Calaza F, Burkholder L, Tysoe WT (2004) Vinyl acetate formation by the reaction of ethylene with acetate species on oxygen-covered Pd(111). J Am Chem Soc 126(47):15384–15385CrossRefGoogle Scholar
  27. 27.
    Stacchiola D, Calaza F, Burkholder L, Schwabacher AW, Neurock M, Tysoe WT (2005) Elucidation of the reaction mechanism for the palladium-catalyzed synthesis of vinyl acetate. Angew Chem 44(29):4572–4574CrossRefGoogle Scholar
  28. 28.
    Samanos B, Boutry P, Montarnal R (1971) The mechanism of vinyl acetate formation by gas-phase catalytic ethylene acetoxidation. J Catal 23(1):19–30CrossRefGoogle Scholar
  29. 29.
    Moiseev II, Vargaftik MN (1992) Perspectives in catalysis, chemistry for the 21st century. Blackwell Scientific, OxfordGoogle Scholar
  30. 30.
    Moiseev II, Vargaftik MN, Syrkin JK (1960) Dokl Akad NaukSSSR 133:377–380Google Scholar
  31. 31.
    Haley R, Tikhov M, Lambert R (2001) The surface chemistry of acetic acid on Pd{111}. Catal Lett 76(3–4):125–130. 3CrossRefGoogle Scholar
  32. 32.
    James J, Saldin DK, Zheng T, Tysoe WT, Sholl DS (2005) Structure and binding site of acetate on Pd(111) determined using density functional theory and low energy electron diffraction. Catal Today 105(1):74–77CrossRefGoogle Scholar
  33. 33.
    Calaza F, Tysoe WT, Stacchiola DJ (2011) Stabilization of carboxylate surface species on Pd(111). Adsorpt Sci Technol 29(6):603–611CrossRefGoogle Scholar
  34. 34.
    Davis JL, Barteau MA (1989) Hydrogen bonding in carboxylic acid adlayers on Pd(111): evidence for catemer formation. Langmuir 5(6):1299–1309CrossRefGoogle Scholar
  35. 35.
    Bowker M, Morgan C, Couves J (2004) Acetic acid adsorption and decomposition on Pd(110). Surf Sci 555(1–3):145–156CrossRefGoogle Scholar
  36. 36.
    Bowker M, Morgan C, Zhdanov VP (2007) Kinetic explosion and bistability in adsorption and reaction of acetic acid on Pd(110). Phys Chem Chem Phys 9:(42)Google Scholar
  37. 37.
    Ormerod RM, Baddeley CJ, Lambert RM (1991) Geometrical and electronic effects in the conversion of acetylene to benzene on Au(111)/Pd and Au/Pd surface alloys. Surf Sci 259(1–2):L709-L713Google Scholar
  38. 38.
    Li Z, Furlong O, Calaza F, Burkholder L, Poon HC, Saldin D, Tysoe WT (2008) Surface segregation of gold for Au/Pd(111) alloys measured by low-energy electron diffraction and low-energy ion scattering. Surf Sci 602(5):1084–1091CrossRefGoogle Scholar
  39. 39.
    Li Z, Gao F, Wang Y, Calaza F, Burkholder L, Tysoe WT (2007) Formation and characterization of Au/Pd surface alloys on Pd(111). Surf Sci 601(8):1898–1908CrossRefGoogle Scholar
  40. 40.
    Boscoboinik JA, Plaisance C, Neurock M, Tysoe WT (2008) Monte Carlo and density functional theory analysis of the distribution of gold and palladium atoms on Au/Pd(111) alloys. Phys Rev B 77(4):045422CrossRefGoogle Scholar
  41. 41.
    Sinfelt JH (1983) Bimetallic catalysts: discoveries, concepts, and applications. Wiley, New YorkGoogle Scholar
  42. 42.
    Dowden DA, Reynolds PW (1950) Some reactions over alloy catalysts. Discuss Faraday Soc 8:184–190CrossRefGoogle Scholar
  43. 43.
    Schwab G-M (1950) Alloy catalysts in dehydrogenation. Discuss Faraday Soc 8:166–171CrossRefGoogle Scholar
  44. 44.
    Sinfelt JH, Carter JL, Yates DJC (1972) Catalytic hydrogenolysis and dehydrogenation over copper-nickel alloys. J Catal 24(2):283–296CrossRefGoogle Scholar
  45. 45.
    Woodruff DP (2002) Surface alloys and alloy surfaces. Elsevier, New YorkGoogle Scholar
  46. 46.
    Rodriguez J (1996) Physical and chemical properties of bimetallic surfaces. Surf Sci Rep 24(7–8):223–287CrossRefGoogle Scholar
  47. 47.
    Gao F, Goodman DW (2012) Pd-Au bimetallic catalysts: understanding alloy effects from planar models and (supported) nanoparticles. Chem Soc Rev 41(24):8009–8020CrossRefGoogle Scholar
  48. 48.
    Baddeley CJ, Tikhov M, Hardacre C, Lomas JR, Lambert RM (1996) Ensemble effects in the coupling of acetylene to benzene on a bimetallic surface: a study with Pd{111}/Au. J Phys Chem 100(6):2189–2194CrossRefGoogle Scholar
  49. 49.
    Kaltchev M, Tysoe WT (2000) The decomposition of molybdenum hexacarbonyl on thin alumina films at high temperatures: formation and reduction of carbides. J Catal196(1):40–45CrossRefGoogle Scholar
  50. 50.
    Delley B (2000) From molecules to solids with the DMol3 approach. J Chem Phys 113(18):7756–7764CrossRefGoogle Scholar
  51. 51.
    Perdew JP, Chevary JA, Vosko SH, Jackson KA, Pederson MR, Singh DJ, Fiolhais C (1992) Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation. Phys Rev B 46(11):6671–6687CrossRefGoogle Scholar
  52. 52.
    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):11169–11186CrossRefGoogle Scholar
  53. 53.
    Vanderbilt D (1990) Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys Rev B 41(11):7892–7895CrossRefGoogle Scholar
  54. 54.
    Methfessel M, Paxton AT (1989) High-precision sampling for Brillouin-zone integration in metals. Phys Rev B 40(6):3616–3621CrossRefGoogle Scholar
  55. 55.
    Blöchl PE (1994) Projector augmented-wave method. Phys Rev B 50(24):17953–17979CrossRefGoogle Scholar
  56. 56.
    Govind N, Petersen M, Fitzgerald G, King-Smith D, Andzelm J (2003) A generalized synchronous transit method for transition state location. Comp Mater Sci 28(2):250–258CrossRefGoogle Scholar
  57. 57.
    Stacchiola D, Tysoe WT (2009) The kinetics of ethylidyne formation from ethylene on Pd(111). J Phys Chem C 113(19):8000–8001CrossRefGoogle Scholar
  58. 58.
    Kuhn WK, Szanyi J, Goodman DW (1992) CO adsorption on Pd(111): the effects of temperature and pressure. Surf Sci 274(3):L611-L618CrossRefGoogle Scholar
  59. 59.
    Szanyi J, Kuhn WK, Goodman DW (1993) CO adsorption on Pd(111) and Pd(100): low and high pressure correlations. J Vac Sci Technol A 11(4):1969–1974CrossRefGoogle Scholar
  60. 60.
    Augustine SM, Blitz JP (1993) The use of DRIFTS-MS and kinetic studies to determine the role of acetic acid in the palladium-catalyzed vapor-phase synthesis of vinyl acetate. J Catal 142(1):312–324CrossRefGoogle Scholar
  61. 61.
    Stacchiola D, Burkholder L, Tysoe WT (2002) Ethylene adsorption on Pd(111) studied using infrared reflection–absorption spectroscopy. Surf Sci 511(1):215–228CrossRefGoogle Scholar
  62. 62.
    Bellamy LJ (1986) The infrared spectra of complex molecules, vol 1. Chapman and Hall, LondonGoogle Scholar
  63. 63.
    Bürgi T (2005) Combined in situ attenuated total reflection infrared and UV–Vis spectroscopic study of alcohol oxidation over Pd/Al2O3. J Catal 229(1):55–63CrossRefGoogle Scholar
  64. 64.
    Stacchiola D, Azad S, Burkholder L, Tysoe WT (2001) An investigation of the reaction pathway for ethylene hydrogenation on Pd(111). J Phys Chem B 105(45):11233–11239CrossRefGoogle Scholar
  65. 65.
    Calaza F, Stacchiola D, Neurock M, Tysoe WT (2010) Kinetic parameters for the elementary steps in the palladium-catalyzed synthesis of vinyl acetate. Catal Lett 138(3–4):135–142CrossRefGoogle Scholar
  66. 66.
    Calaza F, Stacchiola D, Neurock M, Tysoe WT (2005) Structure and decomposition pathways of vinyl acetate on Pd(111). Surf Sci 598(1–3):263–275CrossRefGoogle Scholar
  67. 67.
    Li Z, Calaza F, Plaisance C, Neurock M, Tysoe WT (2009) Structure and decomposition pathways of vinyl acetate on clean and oxygen-covered Pd(100). The J Phys Chem C 113(3):971–978CrossRefGoogle Scholar
  68. 68.
    Redhead PA (1962) Thermal desorption of gases. Vacuum 12:9Google Scholar
  69. 69.
    Calaza F, Gao F, Li Z, Tysoe WT (2007) The adsorption of ethylene on Au/Pd(111) alloy surfaces. Surf Sci 601(3):714–722. 9CrossRefGoogle Scholar
  70. 70.
    Yuan D, Gong X, Wu R (2008) Origin of high activity and selectivity of PdAu(001) bimetallic surfaces toward vinyl acetate synthesis. J Phys Chem C 112(5):1539–1543CrossRefGoogle Scholar
  71. 71.
    Yuan D, Gong X, Wu R (2007) Ensemble effects on ethylene dehydrogenation on PdAu(001) surfaces investigated with first-principles calculations and nudged-elastic-band simulations. Phys Rev B 75(23):233401CrossRefGoogle Scholar
  72. 72.
    Calaza F, Li Z, Garvey M, Neurock M, Tysoe W (2013) Reactivity and selectivity in the Au/Pd(111) alloy-catalyzed vinyl acetate synthesis. Catal Lett 143(8):756–762CrossRefGoogle Scholar
  73. 73.
    Calaza F, Li Z, Gao F, Boscoboinik J, Tysoe WT (2008) The adsorption and reaction of vinyl acetate on Au/Pd(111) alloy surfaces. Surf Sci 602(22):3523–3530CrossRefGoogle Scholar
  74. 74.
    Boscoboinik JA, Calaza FC, Garvey MT, Tysoe WT (2010) Identification of adsorption ensembles on bimetallic alloys. J Phys Chem C 114(4):1875–1880CrossRefGoogle Scholar
  75. 75.
    Li Z, Gao F, Tysoe WT (2008) Surface chemistry of acetic acid on clean and oxygen-covered Pd(100). Surf Sci 602(2):416–423CrossRefGoogle Scholar
  76. 76.
    Li Z, Calaza F, Gao F, Tysoe WT (2007) The adsorption of acetic acid on Au/Pd(111) alloy surfaces. Surf Sci 601(5):1351–1357CrossRefGoogle Scholar
  77. 77.
    Pallassana V, Neurock M, Lusvardi VS, Lerou JJ, Kragten DD, van Santen RA (2002) A density functional theory analysis of the reaction pathways and intermediates for ethylene dehydrogenation over Pd(111). J Phys Chem B 106(7):1656–1669CrossRefGoogle Scholar
  78. 78.
    Calaza F, Mahapatra M, Neurock M, Tysoe WT (2014) Disentangling ensemble, electronic and coverage effects on alloy catalysts: Vinyl acetate synthesis on Au/Pd(111). J Catal 312:37–45CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Chemical Engineering and Materials ScienceUniversity of MinnesotaMinneapolisUSA
  2. 2.Department of Chemistry and Biochemistry, and Laboratory for Surface StudiesUniversity of Wisconsin-MilwaukeeMilwaukeeUSA

Personalised recommendations