Electroreduction of carbon dioxide to liquid fuels: A low-cost, sustainable technology

Abstract

The electrochemical carbon dioxide reduction (ECO2RR) to synthetic fuels or value-added organic compounds constitutes a feasible approach toward decreasing CO2 emissions and securing energy storage. This work analyzes prospective cost-effective electroreduction methods for converting atmospheric CO2 to fuels, particularly to C2 molecules, but conceivably to C6–C8 alkanes, as well. The authors performed calculations of standard reduction potentials for C1–C10 chain-length alkanes. Addressed is the kinetics of electroreduction, including the ECO2RR mediated by various charge transfer catalysts, in aqueous or organic media. Copper and its alloys represent a sort of “magic” electrode material for synthesizing liquid fuels. Selective electrochemical CO2 reduction to HCOOH, CO, and hydrocarbons (including CH4, C2H4, and C2H6) was effective on copper-based nanocatalysts. The authors examine the synthesis of short-chain and possibly long-chain hydrocarbons, revealing expected future routes in CO2 electroreduction. According to the authors’ findings, there are no thermodynamic impediments toward running CO2 electroreductions. Therefore, one concludes that kinetic aspects should be prioritized to identify and test efficient electrocatalysts, which are sufficiently cost-effective for future large-scale use. As of today, selectivity, Faradaic efficiency (FE), and mass yield of ECO2RR to saturated hydrocarbons are still too low for industrial implementation.