Ethanol oxidation reaction activity of highly dispersed Pt/SnO2 double nanoparticles on carbon black

Highly dispersed Pt and SnO2 double nanoparticles containing different Pt/Sn ratios (denoted as Pt/SnO2/CB) were prepared on carbon black (CB) by the modified Bönnemann method. The average size of Pt and SnO2 nanoparticles was 3.1 ± 0.5 nm and 2.5 ± 0.3 nm, respectively, in Pt/SnO2(3:1)/CB, 3.0 ± 0.5 nm and 2.6 ± 0.3 nm, respectively, in Pt/SnO2(1:1)/CB, and 2.8 ± 0.5 nm and 2.5 ± 0.3 nm, respectively, in Pt/SnO2(1:3)/CB. The Pt/SnO2(3:1)/CB electrode showed the highest specific activity and lowest overpotential for ethanol oxidation reaction (EOR), and was superior to a Pt/CB electrode. Current density for EOR at 0.40 and 0.60 V vs. reversible hydrogen electrode for the Pt/SnO2(3:1)/CB electrode decayed more slowly than that for the Pt/CB electrode because of a synergistic effect between Pt and SnO2 nanoparticles. The predominant reaction product was acetic acid, and its current efficiency was about 70%, while that for CO2 production was about 30%.