Title : Catalysts for low-temperature catalytic oxidations using molecular oxygen
Catalytic oxidation processes/technologies are widely applied in the chemical industry and many emission control processes. In these oxidation reactions, employing molecular oxygen (O2) as the oxidant is the most environmentally benign approach, in which activation of O2 by catalysts to obtain the desired active oxygen species is crucial. Furthermore, how to develop catalysts workable under mild reaction conditions is a big challenge. In this work, we report the preparation of various supported mono- and bimetallic catalysts. These catalysts are used for the oxidation reactions of the photo-degradation of methyl orange (MO) in water under visible light, the catalytic wet air oxidation (CWAO) of dyes in wastewaters, preferential oxidation (PROX) of CO in H2-rich gas mixtures and room temperature catalytic removal of formaldehyde (HCHO) in air. It was found that some bimetallic catalysts showed better capability for oxygen activation and catalytic oxidations than the monometallic counterparts. The catalyst structures and the reaction mechanism were investigated in detail. The results show some supported bimetallic catalysts are workable for a number of oxidation reactions at quite low temperatures with high catalytic efficiencies.