Morphological effect of ceria-supported platinum catalyst on low-temperature ethylene oxidation

Three types of Pt/CeO2 catalysts with different support morphologies (rod (CeO2-R), cube (CeO2-C), and octahedron (CeO2-O) were synthesized especially for catalytically oxidizing C2H4 at low temperatures. The as-prepared catalysts exhibited strong shape-dependent catalytic activity in the order of Pt/CeO2-O > Pt/CeO2-C > Pt/CeO2-R. Such unique performance is mainly attributed to the different steps of C2H4 oxidation associated with the variation of oxygen species activated by Pt/CeO2 catalysts. Among the three catalysts, Pt/CeO2-O had the least issue with the accumulation of intermediate species and consequently performed the highest low-temperature C2H4 catalytic oxidation activity. Moreover, the negative impact of water condensation on the catalyst can be readily eliminated by refreshing the catalyst with N2 purging. Overall, this work led to a novel catalytic system for efficient low-temperature ethylene oxidation and a better understanding of the catalytic mechanism, thus benefiting the preservation of fruits and vegetables as one of the applications.