Enhanced CO oxidation activity over a tin oxide surface by platinum doping

Abstract

Pt-doped antimony-tin oxide (Pt/ATO) was synthesized by conventional incipient wetness impregnation. To compare the catalytic properties depending on the different catalytic surface structures, Pt-deposited tin oxide (Pt/TO) and silica (Pt/$SiO_2$) were also prepared. HAADF-STEM images showed a specific surface structure of 0.1 wt% Pt catalysts

especially, single Pt atoms were confirmed for Pt/ATO. DRIFTS for the CO chemisorption and XPS analysis revealed that the Pt elements of Pt/ATO are atomically doped inside the ATO surface. CO oxidation test showed that the Pt/ATO clearly exhibited the highest activity among the 0.1 wt% Pt catalysts by achieving a 50% CO conversion at about 230$\circ$C, which is reduced by about 40$^\circ C$ compared with the ATO. The CO-TPR and $O_2$-TPD results revealed that the surface lattice oxygen on the Pt/ATO is the most active, which means that doping Pt atoms into the ATO surface leads to a better surface lattice oxygen activity of the ATO, resulting in the promotion of the catalytic performance. This work is expected to provide a useful strategy for promoting the catalytic activity of metal oxide catalysts, which can be applied to various catalytic oxidations.