A reusable dual functional Mo₂C catalyst for rapid hydrogen evolution by Mg hydrolysis

Room-temperature hydrogen generation by Mg hydrolysis provides an economical strategy for on-site hydrogen supply with high capacity and environmentally friendly by-products. However, slow reaction kinetics hinders the upscaling of this technology. In this study, a low-cost Mo₂C catalyst was ball milled with Mg to produce a Mg-Mo₂C composite, which can be easily scaled up for manufacturing. The resulting composite exhibited rapid hydrolysis in seawater, generating over 851 mL g⁻¹ hydrogen in 10 min. Moreover, Mo₂C maintained a high catalytic activity after recycling, and a hydrogen yield of over 90% after five cycles. The catalytic mechanism study indicated that the micro galvanic cell and well-combined Mg-Mo₂C interface formed during ball milling significantly enhanced the hydrolysis performance. Therefore, this work provides a cost-efficient and easy scale-up strategy for modifying Mg hydrolysis kinetics and opens new avenues for studying the relationship between material hydrolysis and hydrogen evolution reaction catalysts.