Insight into the Metal-Support Interaction of Pt and β -MnO 2 in CO Oxidation.

Pt-based catalysts exhibit unique catalytic properties in many chemical reactions. In particular, metal-support interactions (MSI) greatly improve catalytic activity. However, the current MSI mechanism between platinum (Pt) and the support is not clear enough. In this paper, the interaction of 1 wt% Pt nanoparticles (NPs) on β -MnO 2 in carbon monoxide (CO) oxidation was studied. The Pt on β -MnO 2 inhibited CO oxidation below 210 °C but promoted it above 210 °C. A Pt/ β -MnO 2 catalyst contains more Pt 4+ and less Pt 2+ . The results of operando DRIFTS-MS show that surface-terminal-type oxygen (M=O) plays an important role in CO oxidation. When the temperature was below 210 °C, Mn=O consumption on Pt/ β -MnO 2 was less than β -MnO 2 due to Pt 4+ inhibition on CO oxidation. When the temperature was above 210 °C, Pt 4+ was reduced to Pt 2+ , and Mn=O consumption due to CO oxidation was greater than β -MnO 2 . The interaction of Pt and β -MnO 2 is proposed.