The effect of particle size on hydrolysis properties of Mg3La hydrides

•H-Mg3La with particle size of [<12] μm yields 7.70 wt.% hydrogen.•The hydrolysis mechanisms of H-Mg3La with different particle sizes are revealed.•Reducing the particle size could improve hydrolysis rate and yield.

The effect of particle size on hydrolysis properties of hydrogenated Mg3La was investigated through fixing the grain size of in-situ formed LaH3 and MgH2 from hydrogenated Mg3La. The hydrolysis rate and hydrogen yield were affected by its particle size. The hydrogenated Mg3La with smaller particle size of [<12] μm had a higher hydrolysis yield of 863 ml g−1 (7.70 wt.%) hydrogen. The surface area and defect of samples were increased through reducing the particle size and thus promoted the complete hydrolysis. Reducing the particle size is an effective and simple method to improve hydrolysis properties of magnesium hydrides-based materials.