Ligand‐Conjugation Engineering Tailors Molecule‐Support Interactions for Efficient CO2 Electroreduction

Abstract

Molecular catalysts offer well‐defined structures, tunable active sites and high selectivity, making them highly promising for energy‐related heterogeneous electrocatalysis. However, the influence of molecule‐support interactions (MSI) on catalytic performance remains poorly understood, largely owing to the complexity of the catalyst‐support interface. Here we investigate the effect of MSI by extending the conjugation structure of plane nickel phthalocyanine (NiPc)–a model molecular catalyst simplifying the interface–to strengthen its interaction with a carbon support, and thereby enhancing the electrocatalytic performance of CO2 reduction reaction. Among NiPc‐based catalysts, nickel anthracocyanine (NiAc) with longest conjugation structure supported by carbon black (NiAc/CB) delivers the strongest MSI and consequently demonstrates the best catalytic performance. Theoretical calculations combined with operando attenuated total reflection surface‐enhanced infrared absorption spectroscopy, demonstrate that the enhanced MSI facilitates electron transfer, promoting both CO2 and the *COOH intermediate activation. NiAc/CB can operate stably at 100 mA cm−2 with nearly 100% CO selectivity at an applied potential of −0.6 V for 60 h. This study provides key insights into the role of MSI in electrocatalysis and offers a strategy for designing more efficient heterogeneous molecular catalysts.