Self-assembly-assisted dynamic placement of noble metals selectively on multifunctional carbide supports for alkaline hydrogen electrocatalysis†

Abstract

Atomically dispersed catalysts are ideal for alkaline hydrogen electrocatalysis with low noble metal loadings. However, previous designs have exhibited insufficient *OH binding and low cell performance, which limit their application in anion-exchange membrane water electrolyzers. In this study, we employed a self-assembly-assisted dynamic placement to prepare atomically dispersed electrocatalysts on heterostructured Mo_xC–C. The multifunctional Mo_xC support bolsters the dynamic placement while optimizing the interfacial water structure. The self-assembly-assisted dynamic placement facilitates the selective loading of atomically dispersed noble metals on Mo_xC at 1373 K by leveraging molecular interactions and metal–support interactions. The dynamic placement enables the construction of interfacial active systems between noble metals and Mo_xC, enhancing the reaction kinetics, stability, and CO tolerance of alkaline hydrogen electrocatalysis. Specifically, selective loading enables the effective utilization of *OH binding sites on Mo_xC, promoting water dissociation by increasing the free-water population in the interfacial water structure. In an anion-exchange membrane water electrolyzer, the designed catalysts exhibited higher cell stability (500 h) than commercial PtRu/C. They also exhibited enhanced performance even with a low noble metal loading (0.060 mg_Pt cm⁻²), achieving the US Department of Energy's 2026 target for proton-exchange membrane water electrolyzers.