Boosting and stabilizing oxygen evolution reaction through Ru single atoms anchored amorphous NiMoOx electrocatalyst

Abstract

Efficient and durable electrocatalysts for the oxygen evolution reaction (OER) are essential for advancing water splitting technologies, which enable sustainable hydrogen production. The integration of amorphous oxide supports with metal single atoms offers a promising strategy to precisely tuning the electronic structure and improving the exposure of active sites. Here, we report an amorphous NiMoO_x support anchored with Ru single atoms (denoted as a-RNMO), which achieves a low cell voltage of 1.78 V at 1 A cm^-2 and noteworthy durability in an anion exchange membrane water electrolyzer. Time-resolved operando Quick X-ray absorption spectroscopy reveals rapid Mo leaching followed by structural reconstruction, culminating in the NiOOH formation. Theoretical calculations suggest a likely "complementary amorphous-electronic" mechanism. It shows that the amorphous structure exposes more active sites and favors the adsorption of intermediates, while Ru single atoms finely modulate the electronic structure. These valuable insights highlight the design of high-performance OER electrocatalysts based on metal single atoms anchored on amorphous oxides.