Engineering Ruthenium Species on Metal-organic Frameworks for Water Electrolysis at Industrial Current Densities

Developing highly active and stable electrocatalysts for hydrogen production at industrial current densities is pivotal to give an impetus to carbon neutrality. Recently, metal-organic frameworks (MOFs) with large surface area and adjustable structures have become a class of promising alternative electrocatalysts, while their low conductivity and poor stability limit their widespread applications. Here, a modified strategy is proposed to stabilize and modulate Ruthenium (Ru) species including Ru single atoms (Ru SAs) and Ru nanoparticles (Ru NPs) on MOFs for enhanced hydrogen evolution reaction (HER). Benefiting from the strong interaction between Ru and MOFs, the synthesized NiFeRuSA+NP-DOBDC (DOBDC: 2,5-dioxido-1,4-benzenedicarboxylate) exhibits an extraordinary HER performance with overpotentials of 25 and 271 mV at 10 and 1000 mA cm-2, respectively. Meanwhile, it enables robust HER at a high current density of 1 A cm-2 over 300 h. Remarkably, the assembled anion exchange membrane (AEM) electrolyzer realizes a low voltage for alkaline water electrolysis. In situ analyses demonstrate that NiFeRuSA+NP-DOBDC enables optimized H2O adsorption and dissociation, and theoretical calculations indicate that Ru SAs and NPs accelerate the Volmer-Heyrovsky pathway, synergistically promoted the HER performance. This work presents a competitive strategy to integrate supported metal species on the MOFs platform to efficiently drive industrial water electrolysis.