Probing the reaction pathway of dimethyl carbonate oxidation on Pt/CeO2 and Pt/Al2O3: Evidence from in situ DRIFTS and DFT computation

Although dimethyl carbonate (DMC) exhibits low photochemical activity compared with other volatile organic compounds (VOCs), it still necessitates elimination due to its significant increasing demand in both stationary and mobile applications. Catalytic oxidation has emerged as an important technique for controlling DMC emissions, yet the reaction mechanism of this process remains unclear. In this study, we utilized Pt/CeO₂ and Pt/Al₂O₃ as model catalysts to investigate the oxidation mechanism of DMC. In situ DRIFTS and DFT calculations reveal that the catalytic oxidation of DMC on Pt/Al₂O₃ and Pt/CeO₂ catalysts both initiate with the cleavage of the C-O bond within the carboxyl group, followed by subsequent oxidation. Notably, the presence of oxygen vacancies on the Pt/CeO₂ surface facilitates the decomposition of DMC, resulting in a lower energy barrier for C-O bond cleavage on Pt/CeO₂ compared to that on Pt/Al₂O₃, which accounts for its superior catalytic activity. The present work not only provides an understanding of the catalytic oxidation process of DMC but also offers preliminary insights into the influence of different active oxygen species on the catalytic reaction.