Insight into the Metal–Support Interaction of Pt and β-MnO2 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) onβ-MnO2in carbon monoxide (CO) oxidation was studied. The Pt onβ-MnO2inhibited CO oxidation below 210 °C but promoted it above 210 °C. A Pt/β-MnO2catalyst contains more Pt4+and less Pt2+. 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-MnO2was less thanβ-MnO2due to Pt4+inhibition on CO oxidation. When the temperature was above 210 °C, Pt4+was reduced to Pt2+, and Mn=O consumption due to CO oxidation was greater thanβ-MnO2. The interaction of Pt andβ-MnO2is proposed.Keywords:metal–support interaction;CO oxidation;terminal-type oxygen;bridge-type oxygen;Pt;MnO2