Boosting catalytic oxidation of propane over CeO2-supported Co3O4 catalyst with strong interfacial interaction and electron transfer

Abstract

Tuning the nanoparticle-support interaction can optimize the catalytic performance of supported metal oxide catalysts for VOCs removal. Herein, a series of Co3O4/CeO2 catalysts with different strengths of interfacial interaction and electron transfer were successfully constructed via various modified wetness impregnation procedures. With the introduction of ammonium hydroxide, citric acid or H2 pretreatment, a stronger interfacial interaction and electron transfer were achieved due to the highly Co3O4 dispersion and CeO2 surface reconstruction. The modified-synthesis Co3O4/CeO2 catalysts, particularly Co3O4/CeO2-CA (citric acid), demonstrated superior catalytic activity (T90 = 296 °C, TOF = 0.337 × 10−3 s−1) and stability for propane oxidation as compared to typical wetness impregnation Co3O4/CeO2-DI (T90 = 314 °C, TOF = 0.121 × 10−3 s−1). Through systematic characterizations and DFT calculation, the strong interfacial interaction and abundant reactive oxygen species facilitate the adsorption and activation of C3H8 and O2 on the catalyst surface, which further promote the intermediates (carbonate/carboxyl species) transformation. These findings highlight interfacial mechanism to catalytic performance optimization of supported metal oxides.