Abstract Industrial application of hydrogen generation from water electrolysis is hindered by the strong dependence of cathodic hydrogen evolution reaction (HER) on Pt catalyst. Herein, this study designs a facile strategy to engine heterointerfaces of Pt and Mo2C to boost the HER catalytic activity and enhance the Pt utilization by considering the catalytic ability of Mo2C toward water dissociation reaction. Co is employed to assist the stable Pt/Mo2C heterointerface engineering as self‐confinement agent. By considering the catalytic ability of metallic Co, carbon cages are in‐situ generated around the CoPt/Mo2C nanoparticles to obtain the CoPt‐Mo2C@C catalyst. Overpotential to deliver 100 mA cm‐2 alkaline HER for CoPt‐Mo2C@C is therefore low to 153 mV while Pt content in CoPt‐Mo2C@C is low to 2.8 wt.%. Pt utilization of CoPt‐Mo2C@C toward alkaline HER catalysis is therefore enhanced by 12 times compared with the commercial Pt/C catalyst, demonstrating the potential for practical applications.
