Exploring the activity of a novel Au/TiC(001) model catalyst towards CO and CO2 hydrogenation

SURFACE SCIENCE

卷:640

Article

Giacomo Asara, Gian^1,2,3  Ricart, Josep M.¹  Rodriguez, Jose A.⁴  Illas, Francesc^2,3 

[1] Univ Rovira & Virgili, Dept Quim Fis & Inorgan, E-43007 Tarragona, Spain

[2] Univ Barcelona, Dept Quim Fis, E-08028 Barcelona, Spain

[3] Univ Barcelona, IQTCUB, E-08028 Barcelona, Spain

[4] Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA

关键词: Syngas;    Methanol synthesis;    CO;    CO2;    Au/TiC;    DFT;   

DOI  :  10.1016/j.susc.2015.01.018

来源: Elsevier

【 摘 要 】

Small metallic nanoparticles supported on transition metal carbides exhibit an unexpected high activity towards a series of chemical reactions. In particular, the Au/TiC system has proven to be an excellent catalyst for SO2 decomposition, thiophene hydrodesulfurization, O-2 and H-2 dissociation and the water gas shift reaction. Recent studies have shown that Au/TiC is a very good catalyst for the reverse water-gas shift (CO2 + H-2 -> CO + H2O) and CO2 hydrogenation to methanol. The present work further expands the range of applicability of this novel type of systems by exploring the catalytic activity of Au/TiC towards the hydrogenation of CO or CO2 with periodic density functional theory (DFT) calculations on model systems. Hydrogen dissociates easily on Au/TiC but direct hydrogenation of CO to methanol is hindered by very high activation barriers implying that, on this model catalyst, methanol production from CO2 involves the hydrogenation of a HOCO-like intermediate. When dealing with mixtures of syngas (CO/CO2/H-2/H2O), CO could be transformed into CO2 through the water gas shift reaction with subsequent hydrogenation of CO2 to methanol. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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