Modulating the Oxygen Evolution Reaction Activity of Bimetallic 2D Polymers by Substituent Effects

An understanding of the structure-activity relationship is crucial for the design and synthesis of high-performance oxygen evolution reaction (OER) catalysts. In this study, the substituent effect of Co─Ni two-dimensional polymer (2DP) on OER is investigated. A series of monolayer bimetallic Co─Ni─MF─R─2DP (─R = ─H, ─CF₃, ─COOCH₃, ─OCH₃, ─N(CH₃)₂) catalysts with accurately defined structures and different electron-donating or electron-withdrawing substituents is selected as the research object. This selection provides an ideal model platform to isolate their intrinsic activity from factors affecting apparent activity, such as electrical conductivity and loading property. It allows for an accurate exploration of the substituent effect on OER in bimetallic materials. The results indicate that the OER activity follows the order CoTAPP─Ni─MF─N(CH₃)₂─2DP > CoTAPP─Ni─MF─OCH₃─2DP > CoTAPP─Ni─MF─H─2DP > CoTAPP─Ni─MF─COOCH₃─2DP > CoTAPP─Ni─MF─CF₃─2DP, which suggests that the catalyst activity is positively correlated with the electron-donating property of the substituents. This work provides an insight into the design of high-performance OER catalysts by the substituent effect.