Recent advances in the measurement of thermochemical, electrochemical and photochemical efficiency of CO2 conversion to value-added products - its challenges and future directions

Converting CO 2 into value-added products is a sustainable method of lowering greenhouse gas emissions while producing useful chemicals and fuels. This review examines advancements in thermochemical, photochemical, and electrochemical approaches for CO 2 conversion. Thermochemical methods use high temperatures and metal oxide catalysts for hydrogenation, photochemical processes utilise light energy and semiconductor catalysts for mild reaction conditions, and electrochemical reduction employs diverse electrodes for selective product formation and renewable energy integration. Recent progress in catalyst design, including heterojunctions and nanostructured composites, has enhanced efficiency and stability. The review discusses the types of CO 2 reduction processes and their advantages. The comparative study of CO 2 conversion efficiency has been compared in detail in terms of the yield, selectivity, TON and faradaic efficiency of thermochemical, photochemical, and electrochemical techniques. To overcome the challenges of the three methods, the researcher developed plasma-assisted CO 2 reduction, which was explored as a future perspective.