Hermawan, A., Amrillah, T., Alviani, V. N., Raharjo, J., Seh, Z. W., & Tsuchiya, N. (2023). Upcycling air pollutants to fuels and chemicals via electrochemical reduction technology. Journal of Environmental Management, 334, 117477. https://doi.org/10.1016/j.jenvman.2023.117477
The intensification of fossil fuel usage results in significant air pollution levels. Efforts have been put into developing efficient technologies capable of converting air pollution into valuable products, including fuels and valuable chemicals (e.g., CO2 to hydrocarbon and syngas and NOx to ammonia). Among the strategic efforts to mitigate the excessive concentration of CO2 and NOx pollutants in the atmosphere, the electrochemical reduction technology of CO2 (CO2RR) and NOx (NOxRR) emerges as one of the most promising approaches. It is even more attractive if CO2RR and NOxRR are paired with renewables to store intermittent electricity in the form of chemical feedstocks. This review provides an overview of the electrochemical reduction process to convert CO2 to C1 and/or C2+ chemicals and NOx to ammonia (NH3) with a focus on electrocatalysts, electrolytes, electrolyzer, and catalytic reactor designs toward highly selective electrochemical conversion of the desired products. While the attempts in these aspects are enormous, economic consideration and environmental feasibility for actual implementation are not comprehensively provided. We discuss CO2RR and NOxRR from the life cycle and techno-economic analyses to perceive the feasibility of the current achievements. The remaining challenges associated with the industrial implementation of electrochemical CO2 and NOx reduction are additionally provided.
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
This research is supported by core funding from: SERC
Grant Reference no. : NA
Acknowledges the financial support from Kurita Water and Environment Foundation (KWEF) under Kurita Overseas Research Grant. T.A. gratefully acknowledges the financial support of internal funding in Universitas Airlangga through Riset Mandat Muda No. 399/UN3.14/PT2020. The Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for Research Activity Start-up (No. 21K21329).