Electric field assisted benzene oxidation over Pt-Ce-Zr nano-catalysts at low temperature

Highlights: • The benzene conversion can be significantly improved by electric field. • The hydrothermal resistance of catalyst can be effectively improved by electric field. • There is synergistic effect between electric field and catalyst. • This work provides a new way to solve the problem of VOCs catalytic removal. A novel catalytic system for benzene oxidation at low temperature is constructed by combining electric field with Pt-Ce-Zr nano-catalyst. The 1 wt% Pt/Ce_0.75Zr_0.25O₂ catalyst assisted by electric field shows the best catalytic performance with 90% benzene conversion at 96.5 °C and excellent water resistance. The effect of electric field on catalysts and catalytic process is comprehensively investigated. The results of XRD, TEM, XPS and H₂-TPR reveal that the electric field show negligible influence on the crystal structure and surface morphology of the catalyst, but it can lead to more oxygen vacancies. Therefore, more adsorbed oxygen with higher activity will be produced on the catalyst surface. The redox performance is improved due to the fact that valence distribution of Pt is changed in forms of more active sites composed of high valence oxides (PtO) generated in electric field. In situ DRIFTS is used to investigate the oxidation process of benzene and the results prove that electric field could accelerate the production and consumption of intermediate products, and produce new intermediate products such as carboxylic acid species, indicating that the introduction of electric field may open up a new rapid reaction path and promote the activation of benzene at low temperature.