Tungsten–Iron–Ruthenium Ternary Alloy Immobilized into the Inner Nickel Foam for High‐Current‐Density Water Oxidation

The pursuit of highly‐active and stable catalysts in anodic oxygen evolution reaction (OER) is desirable for high‐current‐density water electrolysis toward industrial hydrogen production. Herein, a straightforward yet feasible method to prepare WFeRu ternary alloying catalyst on nickel foam is demonstrated, whereby the foreign W, Fe, and Ru metal atoms diffuse into the Ni foam resulting in the formation of inner immobilized ternary alloy. Thanks to the synergistic impact of foreign metal atoms and structural robustness of inner immobilized alloying catalyst, the well‐designed WFeRu@NF self‐standing anode exhibits superior OER activities. It only requires overpotentials of 245 and 346 mV to attain current densities of 20 and 500 mA cm−2, respectively. Moreover, the as‐prepared ternary alloying catalyst also exhibits a long‐term stability at a high‐current‐density of 500 mA cm−2 for over 45 h, evidencing the inner‐immobilization strategy is promising for the development of highly active and stable metal‐based catalysts for high‐density‐current water oxidation process. Self‐standing WFeRu@NF alloying catalyst is deliberately designed by the diffusion of W, Fe, and Ru atoms into the inner layer of nickel foam. Thanks to the high intrinsic OER activity of WFeRu alloy and the surrounded‐compression bringing robust protection environment, the as‐obtained WFeRu@NF composite catalyst shows a superior high‐current‐density water oxidation process.