Combined “Gateway” and “Spillover” effects originated from a CeNi 5 alloy catalyst for hydrogen storage of MgH 2

Efficient catalysts enable MgH 2 with superior hydrogen storage performance. Herein, we successfully synthesized a catalyst composed of Ce and Ni (i.e. CeNi 5 alloy) with splendid catalytic action for boosting the hydrogen storage property of magnesium hydride (MgH 2 ). The MgH 2 —5wt%CeNi 5 composite’s initial hydrogen release temperature was reduced to 174°C and approximately 6.4wt% H 2 was released at 275°C within 10 min. Besides, the dehydrogenation enthalpy of MgH 2 was slightly decreased by adding CeNi 5 . For hydrogenation, the fully dehydrogenated sample absorbed 4.8wt% H 2 at a low temperature of 175°C. The hydrogenation apparent activation energy was decreased from (73.60 ± 1.79) to (46.12 ± 7.33) kJ/mol. Microstructure analysis revealed that Mg 2 Ni/Mg 2 NiH 4 and CeH 2.73 were formed during the process of hydrogen absorption and desorption, exerted combined “Gateway” and “Spillover” effects to reduce the operating temperature and improve the hydrogen storage kinetics of MgH 2 . Our work provides an example of merging “Gateway” and “Spillover” effects in one catalyst and may shed light on designing novel highly-effective catalysts for MgH 2 in near future.