Harnessing Multimetallic Effects via Metal–Phenolic Networks: Feasible On-Surface Assembly and Direct Use as Electrocatalysts

Multimetallic electrodes are gaining significant attention due to their ability to offer diverse electronic configurations and local lattice distortions, optimizing interactions with reactants and intermediates. Metal-phenolic networks (MPNs) present a promising solution by incorporating a wide range of metals and ligands to enhance specific electrochemical reactions. Despite their potential, on-substrate synthesis and direct application of MPNs in electrocatalysis have been limited. This study introduces an elegant, feasible strategy for on-substrate synthesis of MPNs and direct application as the oxygen evolution reaction (OER) catalyst without post-treatment and systematically evaluates the metal ion effect leveraging a multimetallic doping strategy. Notably, the trimetallic complex performs unambiguously better than the bimetallic and monometallic counterparts. TA-CoNiFe@NF demonstrated superior OER performance, with an impressive overpotential of 215 mV at 10 mA·cm^-2, a Tafel slope of 37.3 mV·dec^-1, and excellent stability over 100 h. The computational results illustrate the effect of metal ion doping on the OER mechanism. We demonstrate that phenolic ligands in MPNs offer unique benefits compared to MOFs, alloys, or oxide hybrids, enabling facile on-surface coordination and versatile metal incorporation. This effective, facile approach to multimetallic tuning paves the way for high-performance electrocatalyst designs and synthesis.