Catalyst-free, high selective CO2 reduction in strong acid without alkali cations by mechanical energy-induced triboelectric plasma-electrolytic system

Abstract

Electrochemical CO2 reduction reaction (CO2RR) in an acidic medium is a promising pathway to produce high-valued commodity chemicals. However, the shackles of high selective CO2RR in acids lie in competing hydrogen evolution reaction (HER) on the electrocatalyst surface. Herein, we demonstrate a hybrid triboelectric plasma-electrochemical system driven by mechanical energy in strong acids associated with a gas-liquid interface triboelectric plasma that triggers CO2 reduction at room temperature and atmospheric pressure without catalysts and alkali cations. Record-high selectivity of CO (nearly 100%) and energy efficiency from electrical to chemical energy of 66.7% are achieved, outperforming the previously reported results in advanced electrocatalytic CO2RR. The unprecedented selectivity is attributed to the solvated CO2— radical anions at the gas triboelectric plasma-water interface, which prefers to react with protons to form the key intermediate of COOH. Our finding uncovers the potential of mechanical energy-induced triboelectric plasma electrochemical process in overcoming the selectivity limitations of electrocatalytic reactions.