Boosting CO2 electroreduction to ethylene via CoII-porphyrin regulated Cu2O/Cu nanocomposite

CO2 electroreduction (CO2ER) into high value-added chemicals or fuels is of great significance to solve the current energy shortage and realize the carbon cycle. Although there are reports that Cu-based CO2ER catalysts can achieve multicarbon products, the influence of the microenvironment of Cu-based catalysts on their valence states, interface and CO2ER performance still deserve further investigation. Herein, a Co-II-porphyrin derivative (m-CoTPyP) is used to decorate on Cu2O/Cu nanoparticles with Cu+/Cu-0 mixed valence states and Cu2O/Cu interface for constructing a novel CoTPyP-Cu2O/Cu composite, where m-CoTPyP as ultrathin layer on Cu2O/Cu nanoparticles can not only efficiently promote the adsorption/activation of CO2 and the formation of *CO on the active sites by regulating the microenvironment via H-bonding, but also improve the stability of Cu valence states. Moreover, the Cu+/Cu-0 mixed valence states and abundant Cu2O/Cu interfaces of the Cu2O/Cu nanoparticles significantly enhance the electron transfer rate and CC coupling kinetics. Specifically, the CoTPyP-Cu2O/Cu(1:15) delivers an ethylene (C2H4) Faraday efficiency up to 71 % and excellent stability (>50 h). This work provides a new perspective on the structural design of CO2ER catalyst with synergistic active sites, high Faraday efficiency and selectivity of C2H4 by regulating the microenvironment.