Hydrogen production by hydrolysis of ball milled and cold rolled activated magnesium wastes: case of MSR alloy wastes in NaCl solution

This study investigates the hydrolysis of MSR waste alloys, activated by ball milling and cold rolling, to produce hydrogen. MSR, a magnesium alloy with 2.4% Ag, 2.5% Nd, and 0.4% Zr, is used in applications requiring corrosion or mechanical resistance. The effects of feedstock type (powder vs. chips) and mechanical pre-treatments (ball milling, cold rolling) on hydrogen yield and hydrolysis mechanisms were analyzed through SEM and XRD. Mechanical treatments reduced crystallite size from 183 nm (powder) and 180 nm (chips) to 112 nm and 153 nm, respectively. Powder feedstock, cold rolled 10 times and ball milled for 3 hours, achieved an 89% hydrogen yield after 10 minutes (min) in NaCl solution, with fast kinetics due to defects introduced by the treatments. In contrast, chips with the same pre-treatment yielded 79% after 30 min. Cold rolling alone led to a 20% yield after 30 min. These findings suggest that various industrial waste feedstocks can be used for low-cost, scalable hydrogen production via hydrolysis with simple mechanical treatments. • MSR chips and powder were activated by mechanical treatments. • Hydrolysis produces H 2 with a yield up to 90 % for MSR powder-based materials. • Ball-milling (BM) and cold rolling (CR) increase both the yield and kinetic of H 2 production. • Correlation between defects induce by BM/CR and H 2 production is highlighted.