Oxygen vacancy modulation in CeO2: synergistic effects of zirconium doping and morphological control for promoting dimethyl carbonate synthesis from CO2 and methanol

Abstract

Oxygen vacancies have been demonstrated to play an important role in the conversion of CO₂. In this work, a series of CeO₂ catalysts with different oxygen vacancy contents were synthesized by controlling morphology and doping Zr. In situ DRIFTS results show that the surface oxygen vacancy could promote the adsorption and activation of CO₂, with the adsorption of CO₂ on the surface oxygen vacancy in the form of bidentate carbonate. Meanwhile, the incorporation of Zr promotes the reduction of adjacent Ce⁴⁺ to Ce³⁺, while simultaneously generating oxygen vacancies (O_V). The resulting O_V and hydroxyl groups create frustrated Lewis pair (FLP) active sites to facilitate the adsorption and activation of CO₂, thereby enhancing the yield of dimethyl carbonate (DMC).