Investigation into the roles of interfacial H_(2)O structure in catalytic oxidation of HCHO and CO over CuMnO_(2) catalysts

The rapid deactivation of cost-effective MnO_(2)-based catalysts in humid air limits their application in practice,and the identification of the role of water in an oxidation process is significant for developing water-resistant MnO_(2)-based catalysts.Here,CuMnO_(2)showed a20.3%HCHO conversion in 10 hr at room temperature in humid air with relative humidity of 40%,but deactivated in 3 hr in dry air.The excellent activity and stability of HCHO oxidation in humid air were attributed to the positive effect of H_(2)O on HCHO oxidation to the H_(2)O-HOCH_(2)OH supermolecule assemblies via hydrogen bonds formed on CuMnO_(2).H_(2)O-HOCH_(2)OH supermolecule assemblies tend to be oxidized to carbonate,which is further oxidized to CO_(2).Furthermore,CuMnO_(2)exhibited a much poorer activity of CO oxidation in humid air,but the CO conversion was still 100%in 10 hr in dry air.H_(2)O showed a competitive adsorption effect to CO on CuMnO_(2).CuMnO_(2)could be applied in HCHO elimination in humid air and CO elimination in dry air.