Remarkable enhancement of CO oxidation over Pt1/CeO2 catalysts by atomically dispersed tungsten

Abstract

Ceria-supported atomically dispersed Pt is of great interest in CO oxidation due to their unique catalytic performance and high metal utilization. However, the intrinsic activity of the Pt1/CeO2 single atom catalysts may not be desirable due to the overstabilization of Pt2+ species in the CeO2 matrix. Herein, the local environment of Pt2+ species was tailored by introducing a tungsten oxide additive into the Pt1/CeO2 catalyst, achieving a dramatic improvement in catalytic performance for CO oxidation at low temperatures. The optimized catalyst with 2.5 wt% W loading achieved 100 % CO conversion at 150 °C, which was 120 °C lower than that of the unmodified Pt/CeO2 catalyst. Through in situ infrared spectroscopy and temperature-programmed reduction characterizations, as well as theoretical calculations, we concluded that the tungsten additive modulate the interactions between Pt2+ species and CeO2. Thus, the reducibility of Pt was enhanced, which facilitated the formation of catalytically active metallic Pt0 species during the reaction.