Ordered mesoporous silica-carbon-supported copper catalyst as an efficient and stable catalyst for catalytic oxidative carbonylation

- Cu/MSC behaves high activity and stability than that without silica doping.
- The hybrid structure of Cu/MSC shows enhanced metal support interaction.
- The presence of silica promotes the dispersion of Cu species in MSC support.
- Cu/MSC shows more resistance to aggregate and difficult to be oxidized than Cu/MC.

Ordered mesoporous silica-carbon (MSC) nanocomposites with homogeneously distributed networks were synthesized by the triconstituent co-assembly method and used as supports of Cu catalysts for dimethyl carbonate (DMC) synthesis. The introduced silica contributes to the considerably increased pore size (∼5.8 nm), the enhanced metal-support interaction and high dispersion of Cu nanoparticles (∼3.8 nm) confined in the mesopores. An improved catalytic performance of Cu/MSC is achieved, reaching a DMC selectivity up to 90% at a methanol conversion of 1.5%, and a stable performance during five recycling runs. On the other hand, the benchmark Cu/MC catalyst undergoes a dramatic decrease of methanol conversion, from 1.3 to 1.0%, accompanied by a 27% reduction of DMC space-time yield (STYDMC). The mechanism through which the hybrid carrier affects the catalytic performance is analyzed using DFT calculations. The results show that the binding energy of Cu on MSC is greatly increased while the energy barrier to CO insertion for DMC formation is reduced evidently, thus enhancing the metal-support interaction and, in turn, the catalytic performance.

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