Ethanol oxidation on the ternary Pt-Rh-SnO_2/C electrocatalysts with varied Pt:Rh:Sn ratios

摘要

Ternary Pt-Rh-SnO_2/C electrocatalysts with the atomic ratio Pt:Rh:Sn=3:1:x, where x varies from 2 to 6, were synthesized using the modified polyol method followed by thermal treatment. Several techniques used to characterize these electrocatalysts showed they were composed of homogeneous PtRh alloy and SnO_2, having all three constituents coexisting in single nanoparticles with the average particle size around 1.4 nm and a narrow size distribution. While all the electrocatalysts investigated exhibited high catalytic activity for ethanol oxidation, the most active one had the composition with the Pt:Rh:Sn=3:1:4 atomic ratio. These ternary-electrocatalysts effectively split the C-C bond in ethanol at room temperature in acidic solutions, which is verified using the in situ IRRAS technique.