Efficient Hydrogen-Evolution Catalysis using V-Doped Tungsten Bronze with Atomic Ru Sites Coordinated by Ammonia Channels

The widespread adoption of hydrogen generated through electrochemical water splitting is widely seen as the most promising approach to achieve the urgent goal of carbon neutrality.

Consequently, there has been a strong demand in the field of electrocatalysis over the past decade for the development of materials capable of facilitating the hydrogen evolution reaction (HER) across a wide range of pH conditions. Given their remarkable intrinsic activity, metals from the platinum group (PGM) have been acknowledged for their significant potential and have been utilized in the production of commercial HER catalysts.

A recognized strategy to substantially enhance the utilization of PGM involves the synthesis of atomically dispersed PGM electrocatalysts, built on the principle of preserving their exceptional intrinsic activity. These highly dispersed PGM atoms typically require a support material characterized by an electron-rich coordination environment, typically provided by metallic compounds with numerous vacancies or carbon doped with heteroatoms.

However, the introduction of vacancies and doping into materials tends to be random at the atomic scale, leading to challenges in controlling the distribution of PGM atoms. Thus, even though coordination configurations can be determined through X-ray absorption measurements, effectively managing the spatial arrangement of PGM atoms remains a critical and formidable challenge in the advancement of atomically dispersed PGM electrocatalysts.

Recently, a team of researchers, led by Professor Weilin Xu from the Changchun Institute of Applied Chemistry at the Chinese Academy of Sciences and the University of Science and Technology of China, reported the successful creation of atomic ruthenium with precisely regulated spatial distribution and electronic structure. This achievement was made possible through the unique coordination of ruthenium with ammonia species within the hexagonal channels of vanadium-doped tungsten bronze (V-NHWO).

The special integration of atomic ruthenium not only fosters strong interactions between ruthenium atoms and V-NHWO but also enhances ruthenium utilization. When employed as the electrocatalyst for the HER, it exhibits outstanding performance, achieving significantly higher mass activity compared to Pt/C across a broad pH range.

Theoretical calculations further elucidated that the presence of multi-channel vertically integrated atomic ruthenium sites within the V-doped channels, as well as coexisting ruthenium sites without the multi-channel or vanadium doping effect, leads to improved free energy of water dissociation and hydrogen sorption, ultimately enhancing HER activity. These significant findings have been published in the Chinese Journal of Catalysis.

Source: Chinese Academy of Sciences

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