Boosting Lewis acidic sites via SMSI to enrich oxygen vacancies on Pt–CeO2 catalysts: enhancing efficiency of CO promoted toluene catalysis

Abstract

The optimization of electron transfer on Pt–CeO₂ (PCH) was achieved by adjusting strong metal–support interaction (SMSI). With an increase in SMSI, there was an initial increase followed by a decline in the concentration of total acid sites and oxygen vacancies (O_v) on PCH. The activity of PCH showed the same trend. Lewis acid is the main acid site of PCH, which facilitates the activation of lattice oxygen and the formation of Pt⁰ species, which improves the oxygen cycling ability of PCH. Brønsted acid assists in the formation of O_v. PCH450 showed the best co-catalytic activity for toluene and CO due to its highest Brønsted/Lewis acid value (0.211) and abundant O_v. At a 90% conversion rate (T₉₀), the conversion temperature of toluene in mixed pollutants is advanced by 15 °C and that of CO is delayed by 28 °C. The findings of in situ DRIFTS indicated that CO shortens the reaction path of toluene, and toluene reduces the reaction rate of CO. Therefore, CO promotes toluene catalysis on PCH. Despite the competitive adsorption of mixed pollutants in the co-catalytic system, their reaction pathways remain independent. This study provides a theoretical basis for the thermal catalytic technology of industrial waste gas.