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.