关键词: 二氧化碳, 光电还原, 加氢还原, 离子液体, 矿化

Abstract:

Aimed at obtaining economically valuable fuels or chemicals, the chemical conversion of CO₂ provides a renewable utilization route for CO₂, which is one of the ideal solutions to China's current carbon emission issue. Owing to the chemical stability of CO₂ and complicated reaction pathways, however, the conversion and selectivity of reactions that convert CO₂ are relatively low. The reduction reaction and combination reaction are the two major routes to convert CO₂, which either involves the cleavage of C O bond or maintains the original valence state of carbon in CO₂. In terms of bond cleaving reduction, the hydrogenation of CO₂ has been demonstrated with industrially mature catalysts, but the single pass conversion and selectivity are still far from satisfactory, while the photoelectrochemical reduction of CO₂ is still in the stage of laboratory research. In case of combination reactions that utilize CO₂, it is possible to convert CO₂ into carbonates or polycarbonates, as well as mineralization products. Yet the conversion and economic feasibility of these processes still need further improvements. Under this background, the National Key Research and Development Program of China initiates the “Key fundamental aspects in highly efficient CO₂ conversion and utilization” Program. Future research endeavors will include the explanation of microscopic mechanism and energy transfer pathway during CO₂ hydrogenation and photoelectrochemical reduction, and establishing more controllable synthesis methods of catalysts, which may lead to new breakthroughs of CO₂ reduction. In addition, the interaction between CO₂ and ionic liquids, and the associated catalytic process, as well as the agent enhanced reaction-transfer coupling mechanism will be explored. The phase transformation mechanisms during CO₂ mineralization will also be investigated. These research endeavors will provide fundamental guidance for the mass conversion and utilization of CO₂.

Key words: carbon dioxide, photoelectrochemical reduction, hydrogenation, ionic liquid, mineralization