Highly Efficient Electroreduction of CO2 to C2+ Alcohols on Heterogeneous Dual Active Sites

Electroreduction of CO2 to liquid fuels such as ethanol and n-propanol, powered by renewable electricity, offers a promising strategy for controlling the global carbon balance and addressing the need for the storage of intermittent renewable energy. In this work, we discovered that the composite composed of nitrogen-doped graphene quantum dots (NGQ) on CuO-derived Cu nanorods (NGQ/Cu-nr) was outstanding electrocatalyst for CO2 reduction to ethanol and n-propanol. The Faradaic efficiency (FE) of C2+ alcohols could reach 52.4% with a total current density of 282.1 mA•cm-2 . This is the highest FE for C2+ alcohol with commercial current density to date. Control experiments and density functional theory (DFT) studies demonstrated that the NGQ/Cu-nr could provide dual catalytic active sites, and could stabilize the CH2CHO intermediate to enhance the FE of alcohols significantly through further carbon protonation. The NGQ and Cu-nr had excellent synergistic effect for accelerating the CO2 reduction reaction to alcohols.