Generating strongly basic sites on magnetic nano-stirring bars: Multifunctional integrated catalysts for transesterification reaction

Mass transfer and catalyst recovery are two crucial issues in solid base catalysis, while the cumbersome operation steps and the associated time and energy penalties are still inevitable for conventional catalysts. Achieving the technical upgrades through catalyst design is desirable but challenging because of the difficulty in satisfying diverse demands of different steps. In this work, a magnetically responsive solid base catalyst with the rod-like nanostructure was developed. The rod-like solid base catalysts are composed of Fe₃O₄ cores, silica shells and calcium oxide active sites. The functions of magnetic recovery and stirring were integrated into the catalyst, which applies in both the general catalytic processes and microchannel reactors given their nanoscales. When applied to the synthesis of dimethyl carbonate by one-step transesterification of methanol and ethylene carbonate, an apparent enhancement on turnover frequency value (33.1 h⁻¹) was observed for nano-stirring compared with that tested without stirring (12.1 h⁻¹) within 30 min. The present catalysts may open up new avenues in the development of advanced solid base catalysts. [Figure not available: see fulltext.]