铂/钌纳米催化剂的高一氧化碳耐受性：基于第一性原理计算的见解

High CO tolerance of Pt/Ru nanocatalyst: insight from first principles calculations.

作者信息

Stolbov Sergey, Ortigoza Marisol Alcántara, Adzic Radoslav, Rahman Talat S

机构信息

Department of Physics, University of Central Florida, Orlando, Florida, 32816, USA.

出版信息

J Chem Phys. 2009 Mar 28;130(12):124714. doi: 10.1063/1.3088843.

DOI:10.1063/1.3088843

PMID:19334879

Abstract

Density functional theory based calculations of the energetics of adsorption and diffusion of CO on Pt islets and on the Ru(0001) substrate show that the CO has the lowest adsorption energy at the center of the islet and its bonding increases as it moves to the edge of the island and further onto the substrate. Activation energy barriers for CO diffusion from the islet to the Ru surface are found to be lower than 0.3 eV making the process feasible and leading to the conclusion that this hydrogen oxidation catalyst is CO tolerant because of the spillover of CO from active Pt sites to the Ru substrate. The rate of CO oxidation by OH is found to be substantially enhanced when the former is adsorbed on the edge of Pt islands and the latter on nearby Ru sites.

摘要

基于密度泛函理论对CO在铂岛及Ru(0001)衬底上吸附和扩散能量的计算表明，CO在岛中心的吸附能最低，当它向岛边缘移动并进一步移动到衬底上时，其键合增强。发现CO从岛扩散到Ru表面的活化能垒低于0.3 eV，这使得该过程可行，并得出结论：这种氢氧化催化剂具有CO耐受性，因为CO会从活性铂位点溢出到Ru衬底上。当CO吸附在铂岛边缘而OH吸附在附近的Ru位点上时，发现OH氧化CO的速率会显著提高。