The Effect of Carbon Monoxide Co-Adsorption on Ni-Catalysed Water Dissociation

International Journal of Molecular Sciences

Abas Mohsenzadeh²  Anders Borjesson²  Jeng-Han Wang¹  Tobias Richards² 

[1] Department of Chemistry, National Taiwan University, No. 88, Sec. 4, Ting-Chow Rd, Taipei 11677, Taiwan; E-mail:;School of Engineering, University of Borås, Borås SE 501-90, Sweden; E-Mails:

关键词: water adsorption;    water dissociation;    nickel;    water gas shift reaction;    CO;    H₂O;    DFT;   

DOI  :  10.3390/ijms141223301

来源: mdpi

【 摘 要 】

The effect of carbon monoxide (CO) co-adsorption on the dissociation of water on the Ni(111) surface has been studied using density functional theory. The structures of the adsorbed water molecule and of the transition state are changed by the presence of the CO molecule. The water O–H bond that is closest to the CO is lengthened compared to the structure in the absence of the CO, and the breaking O–H bond in the transition state structure has a larger imaginary frequency in the presence of CO. In addition, the distances between the Ni surface and H₂O reactant and OH and H products decrease in the presence of the CO. The changes in structures and vibrational frequencies lead to a reaction energy that is 0.17 eV less exothermic in the presence of the CO, and an activation barrier that is 0.12 eV larger in the presence of the CO. At 463 K the water dissociation rate constant is an order of magnitude smaller in the presence of the CO. This reveals that far fewer water molecules will dissociate in the presence of CO under reaction conditions that are typical for the water-gas-shift reaction.

【 授权许可】

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