PtxCo/meso-MnOy: Highly efficient catalysts for low-temperature methanol combustion.

Mesoporous manganese oxide (meso-MnO y) and its supported Co, Pt, and Pt x Co catalysts are prepared via the KIT-6-templating and PVA-protected reduction routes, respectively. The excellent catalytic activity of 0.70 wt% Pt 2.42 Co/meso-MnO y is associated with its highly dispersed Pt 2.42 Co alloy NPs, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Pt 2.42 Co NPs and meso-MnO y. • Pt x Co/meso-MnO y is prepared via the polyvinyl alcohol-protected reduction route. • Pt x Co alloy is formed in each of the Pt x Co/meso-MnO y samples. • 0.70 wt% Pt 2.42 Co/meso-MnO y performs the best for methanol combustion. • Pt x Co alloy, O ads content, reducibility, and metal-support interaction govern activity. The KIT-6-templating and polyvinyl alcohol-protected NaBH 4 reduction methods were adopted to prepare the mesoporous manganese oxide (meso-MnO y) and its supported Co, Pt, and Pt x Co catalysts, respectively. Numerous techniques were used to characterize the physicochemical properties of the materials. Catalytic performance of the samples was evaluated for methanol combustion. All of the samples possessed a three-dimensionally ordered mesoporous structure and a surface area of 94–110 m2/g. The Co, Pt, and Pt x Co nanoparticles (NPs) with an average size of 2.2–3.0 nm were uniformly dispersed on the surface of meso-MnO y. The 0.70 wt% Pt 2.42 Co/meso-MnO y sample performed the best: the T 50% and T 90% (temperatures required for achieving methanol conversions of 50 and 90%, respectively) were 50 and 86 °C at a space velocity of 80,000 mL/(g h). The partial deactivation of the 0.70Pt 2.42 Co/meso-MnO y sample due to water vapor or carbon dioxide introduction was reversible. It is concluded that the excellent catalytic activity of 0.70 wt% Pt 2.42 Co/meso-MnO y was associated with its highly dispersed Pt 2.42 Co alloy NPs, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Pt 2.42 Co alloy NPs and meso-MnO y. [ABSTRACT FROM AUTHOR]