CO2 Reduction to Methanol in the Liquid Phase: A Review

Abstract Excessive carbon dioxide (CO 2 ) emissions have been subject to extensive attention globally, since an enhanced greenhouse effect (global warming) owing to a high CO 2 concentration in the atmosphere could lead to severe climate change. The use of 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 into methanol is exothermic, so that low temperature and high pressure are favorable for methanol formation. CO 2 is usually captured and recovered in the liquid phase. Herein, the emerging technologies for the hydrogenation of 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, mechanistic insight on CO 2 ’s conversion into methanol over different catalysts is discussed by taking the available reaction pathways into account.