Fine-tuning Ru catalyst’s microenvironment boosts hydrogen oxidation in alkaline conditions

A team of researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has unveiled a novel strategy to enhance the performance of ruthenium (Ru) catalysts—offering a cost-effective and efficient alternative to platinum (Pt), which is commonly used in hydrogen oxidation reaction (HOR) catalysts, but is expensive and scarce. The study was recently published in Nano Letters.

Ru has emerged as a promising substitute, but under alkaline conditions, its catalytic activity is hindered due to strong adsorption of hydrogen (H*) and hydroxyl (OH*) intermediates, which slows the reaction.

In this study, the researchers led by Prof. Wang Hui, in collaboration with Prof. Zheng Fangcai and Prof. Luo Qiquan of Anhui University—devised a strategy to fine-tune the local electronic environment of Ru. By embedding Ru atoms within manganese oxide lattices, they engineered interfacial Ru–O bonds that were confirmed through electron spin resonance (ESR) spectroscopy at the Steady-State High Magnetic Field Experimental Facility.

This interfacial engineering induced a downward shift in the d-band center of Ru atoms, optimizing the adsorption behavior of reaction intermediates and lowering the energy barrier for water formation. As a result, the Ru catalyst exhibited a remarkable mass activity of 1.26 mA per microgram of Ru in 0.1 M KOH—surpassing a benchmark Ru/C catalyst by 13 times and outperforming commercial Pt/C by 8 times. The catalyst also demonstrated excellent durability and strong resistance to carbon monoxide poisoning.

This study presents a novel strategy for improving HOR catalysts by regulating the interfacial electronic structure. It not only sets a new benchmark for Ru-based materials but also deepens the understanding of how magnetic field technologies like ESR can play a role in advanced catalyst design.