Composition-balanced trimetallic MOFs as ultra-efficient electrocatalysts for oxygen evolution reaction at high current densities

Abstract

Engineering synergistic effects of multi-component catalysts is the key for breakthrough catalyst design. Here, a maximized-entropy approach was proposed to maximize the synergistic effects for maximum enhancements in electrocatalytic efficiencies of multi-component catalysts. Accordingly, composition-balanced iron, cobalt, and nickel based trimetallic MOFs was developed and demonstrated outstanding oxygen evolution reaction (OER) performances with ultra-low overpotentials of 196 and 284 mV achieved at current densities of 10 and 1000 mA cm(-2), respectively, as well as an ultra-low Tafel slope of 29.5 mV dec(-1) in alkaline aqueous media. The catalyst was ultra-stable even when operated at ultra-high current densities, experiencing only 5% loss in current densities, when chronoamperometrically tested at an industrially relevant current density of 1000 mA cm(-2) for over 50 h. in situ Raman spectroscopy study and density functional theory simulations were conducted to explore the OER mechanism and to illustrate the validity of the proposed maximized-entropy approach.