Abstract
The conversion of CO2 to value-added chemicals and solar fuels is a "two birds, one stone" strategy addressing two major challenges, global warming and energy crises, simultaneously. Conventionally, several approaches such as electrochemical, biochemical, and photochemical have been deployed to reduce anthropogenic CO2. However, the thermodynamic and kinetic limitations in these approaches prompted the researchers to develop more efficient CO2 utilization methods such as solar thermochemical CO2 reduction. Nevertheless, a lack of an understanding of the state-of-the-art progress in CO2 utilization motivated us to present a timely comprehensive review. Herein, we summarize the traditional thermochemical-, state-of-the-art thermocatalytic, and solar thermochemical CO2 conversion with a detailed discussion of the working principles, modern techniques used, and mechanistic insights. Moreover, considering the kinetic and thermodynamic perspectives, the choice of catalysts and reaction conditions to selectively produced chemicals such as methanol, formic acid, dimethyl ether, and hydrocarbons, have been discussed. Lastly, we have highlighted the challenges and future trends for ameliorating the CO2 conversion efficiency and commercial-scale CO2-based solar fuel synthesis. Therefore, this review would be of substantial importance to the students and researchers to understand the CO2 conversion mechanism and to facilitate the breakthrough progress for scientific and industrial advances in carbon capture and utilization.