Catalytic role of pre-adsorbed CO in platinum-based catalysts: the reduction of SO2 by CO on PtlAum(CO)n

• Published in: Physical chemistry chemical physics : PCCP 2013-08, Vol.15 (31), p.12846-12851
• Main Authors: Gao, Guo-Ping, Wei, Shi-Hao, Gu, Xiao, Duan, Xiang-Mei
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon Monoxide - chemistry; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Gold - chemistry; Oxidation-Reduction; Platinum - chemistry; Sulfur Dioxide - chemistry; Surface Properties; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c3cp44712j

Using density functional theory, we have investigated the catalytic properties of bimetallic complex catalysts Pt l Au m (CO) n ( l + m = 2, n = 13) in the reduction of SO 2 by CO. Due to the strong coupling between the C-2p and metal 5d orbitals, pre-adsorption of CO molecules on the Pt l Au m is found to be very effective in not only reducing the activation energy, but also preventing poisoning by sulfur. As result of the coupling, the metal 5d band is broadened and down-shifted, and charge is transferred from the CO molecules to the Pt l Au m . As SO 2 is adsorbed on the catalyst, partial charge moves to the anti- bonding orbitals between S and O in SO 2 , weakening the SO bond strength. This effect is enhanced by pre-adsorbing up to three CO molecules, therefore the SO bonds become vulnerable. Our results revealed the mechanism of the excellent catalytic properties of the bimetallic complex catalysts. Using density functional theory, we have investigated the catalytic properties of bimetallic complex catalysts Pt l Au m (CO) n ( l + m = 2, n = 13) in the reduction of SO 2 by CO.