Effects of atom arrangement and thickness of Pt atomic layers on Pd nanocrystals for electrocatalysis. (1st May 2018)

• Record Type: Journal Article
• Authors: Lin, Yan-Fen; Tian, Na; Xiao, Chi; Sheng, Tian; Li, Gen; Zhang, Feng-Yang; Ye, Jin-Yu; Xu, Bin-Bin; Zhou, Zhi-You; Sun, Shi-Gang
• Is Part Of: Electrochimica acta. Volume 271(2018)
• Page Start: 519
• Page End: 525
• Publication Date: 2018-05-01
• Subjects: Ethanol oxidation -- High-index facets -- Pt overlayers -- Pd tetrahexahedron -- Electrochemical in situ FTIR; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.03.124
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Depositing ultrathin Pt layer on less expensive substrates is an effective way to increase the catalytic activity and utilization efficiency of Pt catalyst in direct alcohol fuel cells. In this study, electrocatalytic properties of Pt atomic layer on Pd nanocrystals (NCs) was studied by changing the thickness of Pt layers and the surface structure of Pd NCs. We prepared 1–5 atomic Pt layers on {730}-faceted tetrahexahedral Pd nanocrystals (THH Pd@Ptn NCs) and on {111}-preferential Pd NCs. For both cases, Pt monolayer has a strong electronic effect from Pd NCs, while Pt bilayers have a moderate effect. In comparison with the {111}-preferential Pd@Ptn NCs, the THH Pd@Ptn NCs exhibit about 3 times higher catalytic activity towards ethanol electrooxidation. It has measured that the THH Pd@Pt2 NCs exhibit the highest catalytic activity amongst all THH Pd@Ptn (n = 1–5) NCs and THH Pt NCs, which is interpreted by a synergy of electronic effect and surface atom arrangement effect. Highlights: A few (n = 1–5) Pt atomic layes on THH Pd NCs with high-index facets were prepared. Adsorption of oxygen and CO, and ethanol oxidation on Pt atomic layes were studied. Monolayer Pt has a strong electronic effect, while bilayer Pt has a moderate effect. Bilayer Pt on THH Pd NCs exhibits the highest catalytic activity towards ethanol oxidation. Synergy of electronic effect and atom arrangement effect was evidenced.