Immobilizing ultrafine bimetallic PtAg alloy onto uniform MnO2 microsphere as a highly active catalyst for CO oxidation

摘要

Herein, a facile glycol reduction route is successful employed to synthesize bimetallic PtAg alloys with homogeneous distribution of sizes and elements. Experimental studies reveal that the ultrafine PtAg alloys with well-defined sizes from around 3.3 nm to 5.8 nm are immobilized onto MnO(2 )microsphere, which remarkably enhances the catalytic performances for CO oxidation. Importantly, quasi in-situ X-ray photoelectron spectroscopy (XPS) result reveals that both Mn and Pt ions on the surface of catalysts would realize alternating reduction-oxidation by CO and O-2 molecules, and the oxygen vacancy sites could be replenished and excited by gas-phase O-2.

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