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

A maximized-entropy concept was proposed and demonstrated to maximize the synergistic effects for maximum enhancements in electrocatalytic efficiencies of multi-component catalysts. [Display omitted] •Maximized-entropy concept proposed for highly efficient multi-component catalysts•Trimetallic MOFs grown in-situ on Ni foam via a one-step hydrothermal process•Achieve ultralow η10 & η1000 of 196 and 284 mV, respectively for OER•Attain smallest Tafel slope of 29.5 mV dec−1•Exhibit ultrastability at 1000 mA cm−2 for OER over 50 h 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.