Efficient Hydrogen Oxidation Catalyzed by Strain‐Engineered Nickel Nanoparticles

The hydroxide‐exchange membrane fuel cell (HEMFC) is a promising energy conversion device. However, the development of HEMFC is hampered by the lack of platinum‐group‐metal‐free (PGM‐free) electrocatalysts for the hydrogen oxidation reaction (HOR). Now, a Ni catalyst is reported that exhibits the highest mass activity in HOR for a PGM‐free catalyst as well as excellent activity in the hydrogen evolution reaction (HER). This catalyst, Ni‐H₂‐2 %, was optimized through pyrolysis of a Ni‐containing metal‐organic framework precursor under a mixed N₂/H₂ atmosphere, which yielded carbon‐supported Ni nanoparticles with different levels of strains. The Ni‐H₂‐2 % catalyst has an optimal level of strain, which leads to an optimal hydrogen binding energy and a high number of active sites.