Promoting Low-Temperature Toluene Oxidation via Pt–O–Fe Interfacial Sites in a Pt/CuO–Fe3O4 Catalyst

Electronic metal-support interaction (EMSI) has been widely explored in the catalytic degradation of volatile organic compounds (VOCs) owing to the formation of special interfacial sites. Herein, the EMSI effect was engineered by constructing the serial Pt catalysts supported on CuO-Fe3O4 bimetal oxide (Pt/CFO). Among them, the 0.5Pt/CFO catalyst with 0.5 wt % Pt loading exhibited an outstanding catalytic activity, with T90 (the temperature of 90% toluene conversion) lowered to 185 °C, and displayed excellent stability and water resistance. Comprehensive physicochemical characterizations revealed that an evident electron transfer occurred via the interface structure (Pt-O-Fe), producing the positively charged Pt (Ptδ+) and abundant Fe2+ species. Notably, the increased electron density around the Fe species weakened the Fe-O bond and thus activated the surface lattice oxygen (Olatt). Further, temperature-programmed desorption experiments and in situ diffuse reflectance infrared Fourier transform spectroscopy results demonstrated that the electron-deficient Ptδ+ was conducive to the adsorption and activation of toluene at low temperature. Consequently, the deep oxidation of toluene was achieved with the participation of Olatt, benefiting from the Ptδ+-O-Fe2+ interfacial sites with synergistic catalysis for toluene adsorption and oxygen activation. This work provides an interesting idea to explore the relationship between the electron transfer effect and highly efficient VOC abatement.