The synergic degradation mechanism and photothermocatalytic mineralization of typical VOCs over PtCu/CeO2 ordered porous catalysts under simulated solar irradiation

Abstract

The major challenges facing catalysts for mineralization of volatile organic compounds (VOCs) include poor photocatalytic efficiency, high cost of thermocatalytic oxidation, and low stability. Here, a highly active and stable PtCu/CeO2 ordered porous nanostructure catalyst was synthesized and efficiently applied in the instant mineralization of paraffinic VOCs under photothermocatalytic conditions. Optical and morphological characterization shows that low loadings of PtCu alloy clusters on CeO2 surfaces lead to enhanced light harvesting, improved charge separation, and increased capacity for reactive oxygen generation and then promote a dynamic balance of Cu1+,2+/Cu0 with high photothermocatalytic stability. Reaction kinetics calculations and carbon deposits investigation reveal that photothermocatalytic synergism mainly comes from the acceleration of the Mars–van Krevelen redox cycle by photocatalysis and the enhancement of coke resistance by thermocatalysis. The strategy here would provide insight into the design of highly effective catalysts, as well as in-depth understanding of the synergic mechanism of photothermocatalytic mineralization of refractory VOCs.