Enhanced hydrogen evolution reaction activity of FeM (M = Pt, Pd, Ru, Rh) nanoparticles with N-doped carbon coatings over a wide-pH environment

The alloy catalyst formed by transition metal and a small amount of noble metal has become the most promising substitute for M-based (M = Pt, Pd, Ru, Rh) catalyst. However, due to the direct exposure of the metal core to the electrolyte, it is vulnerable to corrosion and oxidation, which in turn reduces the catalytic stability and is becoming a major obstacle to sustainable hydrogen production. The present work addresses this issue by developing a one-step immersion-adsorption-pyrolysis strategy for synthesizing FeM alloy nanoparticles with N-doped carbon coatings (FeM@CN) for use as electrocatalysts in the HER. The deliberately designed metal-organic framework material was used as the precursor of catalyst synthesis to achieve the carbon coatings and simultaneously the heteroatom in-situ doping for the alloy nanoparticles. The optimal FePt@CN demonstrates excellent catalytic stability and HER activity in an acidic electrolyte medium. The reactions obtain a small overpotential of 28 mV to achieve current densities of 10 mA cm⁻², which are comparable to a high-performance commercial Pt/C electrocatalyst with a much higher Pt loading. The FeRu@CN also demonstrates an outstanding performance with an overpotential of only 18 mV to achieve a current density of 10 mA cm⁻² in an alkaline medium.