The direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol has been widely acknowledged to have great potential and attracted much interest. However, DMC production is always thermodynamically limited and difficult to proceed. An elaborate catalyst is critical to realize efficient DMC production, but it faces big challenges. Herein, ETS-10 zeolite was assembled with precalcined CeO2 in the shape of an octahedron by the direct grinding method. The resulted CeO2 (600 °C)@HETS-10 catalyst was endowed with improved Lewis acid–base pair of sites, which is conducive to the adsorption-activation of methanol and CO2. More importantly, methanol, rather than CO2, was proven to dominate DMC formation by being activated to t-H3CO* species on Lewis acid sites (exposed Ti4+/Ce3+), which can rapidly couple with bidentate carbonate produced on Lewis basic sites (oxygen vacancies). Thus, the synthesis of DMC was significantly boosted with an extraordinary yield of DMC (538.38 mmol·gcat–1) and methanol conversion (93.8%) under mild conditions. This work provides pioneering insight into the development of functional catalysts for CO2-methanol conversion.
Xiang et al. (Thu,) studied this question.