Implanting Numerous Hydrogen‐Bonding Networks in a Cu‐Porphyrin‐Based Nanosheet to Boost CH4 Selectivity in Neutral‐Media CO2 Electroreduction

Abstract The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well‐designed electrocatalysts with advantages like proton generation/transferring and intermediate‐fixating for efficient CO2RR are much preferred yet largely unexplored. In this work, a kind of Cu‐porphyrin‐based large‐scale (≈1.5 μm) and ultrathin nanosheet (≈5 nm) has been successfully applied in electrochemical CO2RR. It exhibits a superior FE of 70 % with a high current density (−183.0 mA cm−2) at −1.6 V under rarely reported neutral conditions and maintains FE >51 % over a wide potential range (−1.5 to −1.7 V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen‐bonding networks through the integration of diaminotriazine with Cu‐porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen‐bonding‐based materials as efficient CO2RR catalysts.