Electrochemical CO<sub>2</sub>/CO Reduction and C–C Coupling Path for Mimicking Fischer–Tropsch Synthesis over Cadmium Electrodes
Ju Young Maeng, Seon Young Hwang, Young Jun Kim, Ilsun Yoon, Chang Woo Myung, Choong Kyun Rhee, Youngku Sohn
Abstract
Converting CO 2 into C n >2 hydrocarbons has been a significant challenge, but recent research has shown that cadmium (Cd) can be used to produce C 2–7 hydrocarbons (C n H 2 n and C n H 2 n +2 ) directly through electrochemical CO 2 reduction in a K 2 HPO 4 /KH 2 PO 4 buffer. The production of hydrocarbons was found to be enhanced by engineering the interface of the Cd surface with other transition metals. This process imitates the Fischer–Tropsch (F–T) synthesis, which involves surface polymerization reactions that couple carbon atoms together, resulting in the formation of long-chain hydrocarbons via the insertion of CO and CH x molecules. While the formate path was almost completely suppressed, the CO path remained. While the current Faradaic efficiency may be low, this study highlights the potential of electrochemical CO reduction for Cd. The study demonstrates that CO and H can directly participate in F–T synthesis through electrochemistry. Furthermore, Cd was observed to recrystallize into stacked wall structures resembling flowers after the electrochemical process. As a result, this research provides crucial insights that can aid in a better understanding of C–C coupling paths via electrochemistry.