Sustainable technologies for the reclamation of greenhouse gas CO2

The reclamation of greenhouse gas CO2 which brings the new opportunity in the area of C1 chemistry will become a new hot topic in the research frontier of green catalysis. The topics on the reclamation of CO2 discussed in the review are as follows: (i) hydrogenation to methanol, dimethyl ether, methane, alkene, formic acid, etc. (ii) reaction with hydrocarbons, including CO2 reforming of methane to syngas; hydrocarbons oxidation to alkene, aldehyde, and carboxylic acid; C1-C3 hydrocarbons and aromatics carboxylation. (iii) reaction with oxy-organics, such as methanol, propylene glycol and epoxide, to obtain valuable chemicals and materials. (iv) Reaction of CO2 with others. In this review, the performance of the catalysts involved was evaluated, and the underlying reaction mechanisms of CO2 activation by catalysis were analyzed. In addition, opportunities and prospects in the other utilization of carbon dioxide were introduced, such as conversion of carbon dioxide to biodiesel and biogas by biological microalgae technologies, progress of CO2 utilization as new hydrogen storage materials. Carbon dioxide has good chemical stability, and the activation of CO2 is believed to be the key of the whole utilization process. It is necessary to develop suitable catalysts with high activity and selectivity in the further work. The exploitation of homogeneous catalyst may greatly enhance the conversion and selectivity of the reaction. Multi-functional catalysts with desirable adsorption-catalysis activity also need to be developed in order to directly use carbon dioxide emitted from different practical sources. Moreover, the investigation of metal ligand coordination catalysis, photocatalysis and biological biomimetic catalysis is beneficial to both the utilization of new energy and the mitigation of greenhouse gas.