Bimetallic Conductive\nMetal Organic Framework Nanorods\nwith Atomically Dispersed Fe and Co Sites for Efficient Oxygen Evolution

Exploring efficient nonpyrolysis conductive metal organic\nframeworks\nwith high intrinsic reactivity is critical for their application in\nthe electrocatalytic field. Herein, we present electronically conductive\nπ-d-conjugated Co and Fe bimetallic MOF-CoFe-hexahydroxytriphenylene\n(CoFe-HHTP) nanorods with atomically dispersed Co–O<sub>6</sub> and Fe–O<sub>6</sub> sites for efficient oxygen evolution\nreaction (OER) catalysis. The introduction of Fe not only increases\nthe electronic conductivity of Co-HHTP with an order of magnitude\nfavoring the electronic transfer during OER catalysis but also tailors\nthe electronic structure of Co, leading to a downshift of Co d-band\ncenter that weakens the adsorption of oxygen intermediates on Co sites.\nAs a result, the as-prepared CoFe-HHTP exhibits a significantly improved\nOER activity showing a lower overpotential (316 mV) at a current density\nof 10 mA cm<sup>–2</sup> in an alkaline electrolyte compared\nwith pure Co-HHTP (370 mV), outperforming commercial RuO<sub>2</sub> (329 mV). CoFe-HHTP also displays a superior electrochemical durability\nwith only a slight change of potential after a 200 h test at 10 mA\ncm<sup>–2</sup>, outperforming pure Co-HHTP (140 h). The improved\ndurability was due to the hindered dissolution of Co by suppressing\nstructural transformation in the presence of Fe in the alkaline electrolyte.\nWhen CoFe-HHTP was used as the anode catalyst, a superior alkaline\nelectrolyzer performance was obtained with a cell voltage of 1.821\nV at 500 mA cm<sup>–2</sup> and a stable operation of 50 h.\nThis methodology offers insights into the design and synthesis of\nconductive MOF-based catalysts for efficient OER catalysis.