LAUSR

Excessive carbon dioxide (CO 2 ) emission has attracted extensive attention globally since an enhanced greenhouse effect (global warming) due to a high CO 2 concentration in the atmosphere could lead to severe climate change. Using solar energy and other renewable energy to produce low-cost hydrogen, which is used to reduce CO 2 to produce bulk chemicals, such as methanol, is a sustainable strategy for reducing carbon dioxide emissions and carbon resources. CO 2 conversion to methanol is exothermic, so that low temperature and high pressure are favorable for the methanol formation. On the other hand, CO 2 is usually captured and recovered in the liquid phase. Herein, the emerging technologies of hydrogenating CO 2 to methanol in the condensed phase are reviewed. The development of homogeneous and heterogeneous catalysts for this important hydrogenation reaction is summarized. Finally, the mechanistic insight of CO 2 conversion to the methanol formation over different catalysts is discussed by taking the available reaction pathways into account.