Regulating the surface local environment of MnO2 materials via metal-support interaction in Pt/MnO2 hetero-catalysts for boosting methanol oxidation

Abstract

Rational use of the strong metal-support interaction (SMSI) is an important way to achieve the complete destruction of volatile organic compounds (VOCs). In order to investigate the influence of SMSI on the catalytic oxidation of VOCs, three Pt/MnO2 hetero-catalysts, i.e., Pt/α-MnO2, Pt/γ-MnO2 and Pt/δ-MnO2, were synthesized and then applied to the catalytic oxidation of methanol. The results showed that, compared with their corresponding pure MnO2, the temperatures (T90) at which 90% of methanol is converted to CO2 for the above three synthesized catalysts were reduced by 54 °C, 67 °C and 32 °C, respectively. The Pt/α-MnO2 catalyst has the best reducibility at lower temperature (T90 = 91 °C). Multiple characterization analyses confirm that the interaction between Pt and MnO2 support can increase the amount of Mn4+ and surface lattice oxygen on the catalyst surface. Thanks to the optimization of local reaction environment on the catalyst surface, Pt/MnO2 hetero-catalysts have better low temperature reduction capacity and stronger VOC deep oxidation capacity than corresponding pure MnO2 catalysts.