Exploring Nanoengineered Manganese Oxide‐Based Composite Catalysts for Acidic Water Electrooxidation

Developing efficient, acid‐stable, and noncritical oxygen evolution reaction (OER) catalysts is crucial for the advancement of multiple renewable energy technologies. In this work, the design and synthesis of manganese oxide‐based catalysts (MnO x ) are investigated, combined with varying ratios of gold nanowires (Au NWs)—both considered noncritical raw materials—to fabricate composite materials for use in acidic OER. The experimental findings indicate that approximately two‐thirds of MnO x within the catalyst layer is fully utilized when Mn is present at an atomic ratio of 5:1 to Au. This is primarily attributed to the incorporation of Au NWs, which markedly improves the conductivity of the catalyst layer. Cyclic voltammetry analyses suggest that in the composite with an atomic ratio of 5 Mn to 1 Au, Mn 3+ remains persistently present on the surface of MnO x throughout testing. This not only maintains the enhanced OER activity, but also significantly reduces Mn dissolution. Moreover, gas diffusion electrode measurements demonstrate that the “5Mn + 1Au” composite can achieve a current density of 1000 mA cm −2 . This observation reinforces the concept of employing composite electrocatalysts derived from noncritical raw materials and highlights their potential for catalyzing the OER in acidic environments.