Homonuclear/Heteronuclear Bimetallic Conjugated Coordination Polymers with Customized Oxygen Evolution Pathway

The reasons for the generally superior performance of synergistic effects in bimetallic catalysts in the oxygen evolution reaction (OER) are not fully understood, largely due to the complexity of catalyst structures and the challenges associated with synthesizing long-range atomic ordering catalysts. In this study, we present a series of two-dimensional (2D) conjugated bimetallic coordination polymers (c-CPs) involving Co or Ni with unambiguous and nearly identical geometry structures for the electrocatalysis of OER, which are highly suitable for discussions on structure-property correlations. The heteronuclear CoNi-PI unexpectedly alters the OER catalytic mechanisms from adsorbate evolution mechanism those observed in homonuclear CoCo-PI and NiNi-PI to the kinetically faster oxide path mechanism, exhibiting high stability and an ultralow overpotential of 282 mV even at 100 mA cm^-2 with a Tafel slope of approximately 42 mV dec^-1. This study presents an extremely rare crystalline heteronuclear bimetallic catalyst with excellent catalytic properties, promising significant influences in catalyst development research.