Highly Selective CO2 Electroreduction to C2H4 Using a Dual‐Sites Cu(II) Porphyrin Framework Coupled with Cu2O Nanoparticles via a Synergetic‐Tandem Strategy

Low *CO coverage on the active sites is a major hurdle in the tandem electrocatalysis, resulting in unsatisfied C2H4 production efficiencies. In this work, we developed a synergetic‐tandem strategy to construct a copper‐based composite catalyst for the electroreduction of CO2 to C2H4, which was constructed via the template‐directed polymerization of ultrathin Cu(II) porphyrin organic framework incorporating atomically isolated Cu(II) porphyrin and Cu(II) bipyridine sites on a carbon nanotube (CNT) scaffold, and then Cu2O nanoparticles were uniformly dispersed on the CNT scaffold. The presence of dual active sites within the Cu(II) porphyrin organic framework create a synergetic effect, leading to an increase in local *CO availability to enhance the C−C coupling step implemented on the adjacent Cu2O nanoparticles for further C2H4 production. Accordingly, the resultant catalyst affords an exceptional CO2‐to‐C2H4 Faradaic efficiency (FEC2H4) of 71.0 % at −1.1 V vs reversible hydrogen electrode (RHE), making it one of the most effective copper‐based tandem catalysts reported to date. The superior performance of the catalyst is further confirmed through operando infrared spectroscopy and theoretic calculations.