Influence of Cu incorporation on activated carbon for CO2 adsorption and electrocatalytic hydrogen evolution reaction

Abstract

Electrocatalytic hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR) have emerged as promising approaches toward a sustainable and green society. In this study, potassium citrate-derived activated carbon (ACK) was synthesized and incorporated with copper (Cu) for electrocatalytic reduction under CO2 and N2 flows. The ACK sample exhibited high CO2 adsorption properties to generate different carbonate species and served as an electrocatalyst after Cu incorporation. To understand the competitive reactions of HER and CO2RR, different reaction conditions were applied. Under a CO2 flow, the Cu-ACK sample revealed a high and long-term current density of 0.9 V, and H2 (2.642 mmol) was determined as the major product, and CH3COOH, and C2H5OH as minor products. A reaction mechanism was proposed to elucidate the reaction path for the electrocatalytic CO2RR and HER.