Why is ethylene considered the bread and butter of industries? This colorless gas serves as a feedstock for various petrochemicals such as plastics, vinyl, and synthetic rubber, in much the same way that bread and butter are essential to the nation’s food supply. The technology that enables the electrochemical reduction of carbon dioxide, which produces ethylene from CO2 instead of petroleum, has recently become a hot topic. Recently, a Korean research team thoroughly analyzed the role of cations in converting CO2 into valuable chemicals.
A joint research team led by Prof. Chang Hyuck Choi (Department of Chemistry) of POSTECH and Prof. Hyungjun Kim (Department of Chemistry) of KAIST found that CO2 electroreduction is highly dependent on the presence and concentration of cations . The results differ from the conventional view that alkali metal cations do not influence the reaction.
Electrochemical carbon dioxide reduction is a technology that produces valuable chemicals from the reaction of CO2 and water. The process has gained attention as an environmentally friendly method that emits no carbon and uses renewable energy sources. Many efforts are underway to make this technology commercially viable, but uncertainty over the mechanism behind the reaction has been a stumbling block.
POSTECH-KAIST researchers used atomic-scale simulation based on quantum mechanics to examine the mechanistic role of alkali metal (M+) cations on reactants at the catalyst-electrolyte interface. Their simulation showed the ability to coordinate cations to any intermediate species *1, which was CO2 in this case, stimulated the reaction. They also confirmed their concentration adjustment figures to prove that the higher the cation concentration, the higher the rate of ethylene production.
Based on these research results, the research team further secured a catalyst-electrolyte interface control mechanism to increase the concentration of cations in the electric double layer around the electrode and succeeded in producing high performance ethylene.
Professor Choi explained: “Our research revealed that the complexation of M+ to the CO2 intermediate is an essential mechanism for the reduction of CO2 to produce ethylene. This mechanism suggests a new approach to identify high-performance catalytic conditions as well as a significant step towards carbon neutrality by supporting fuel cell and water electrolysis technologies.