Recent advances in CO capture and reduction.

Given the continuous and excessive CO emission into the atmosphere from anthropomorphic activities, there is now a growing demand for negative carbon emission technologies, which requires efficient capture and conversion of CO to value-added chemicals. This review highlights recent advances in CO capture and conversion chemistry and processes. It first summarizes various adsorbent materials that have been developed for CO capture, including hydroxide-, amine-, and metal organic framework-based adsorbents. It then reviews recent efforts devoted to two types of CO conversion reaction: thermochemical CO hydrogenation and electrochemical CO reduction. While thermal hydrogenation reactions are often accomplished in the presence of H, electrochemical reactions are realized by direct use of electricity that can be renewably generated from solar and wind power. The key to the success of these reactions is to develop efficient catalysts and to rationally engineer the catalyst-electrolyte interfaces. The review further covers recent studies in integrating CO capture and conversion processes so that energy efficiency for the overall CO capture and conversion can be optimized. Lastly, the review briefs some new approaches and future directions of coupling direct air capture and CO conversion technologies as solutions to negative carbon emission and energy sustainability.