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 <i>T</i>₉₀ (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 (Pt^δ+) 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 (O_latt). Further, temperature-programmed desorption experiments and in situ diffuse reflectance infrared Fourier transform spectroscopy results demonstrated that the electron-deficient Pt^δ+ was conducive to the adsorption and activation of toluene at low temperature. Consequently, the deep oxidation of toluene was achieved with the participation of O_latt, benefiting from the Pt^δ+-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.