Combined Gateway and Spillover effects originated from a CeNi5 alloy catalyst for hydrogen storage of MgH2

Efficient catalysts enable MgH2 with superior hydrogen storage performance. Herein, we successfully synthesized a catalyst composed of Ce and Ni (i.e. CeNi5 alloy) with splendid catalytic action for boosting the hydrogen storage property of magnesium hydride (MgH2). The MgH2-5wt%CeNi5 composite's initial hydrogen release temperature was reduced to 174 degrees C and approximately 6.4wt% H-2 was released at 275 degrees C within 10 min. Besides, the dehydrogenation enthalpy of MgH2 was slightly decreased by adding CeNi5. For hydrogenation, the fully dehydrogenated sample absorbed 4.8wt% H-2 at a low temperature of 175 degrees C. The hydrogenation apparent activation energy was decreased from (73.60 +/- 1.79) to (46.12 +/- 7.33) kJ/mol. Microstructure analysis revealed that Mg2Ni/Mg2NiH4 and CeH2.73 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 MgH2. 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 MgH2 in near future.

Automated summary

Efficient catalysts composed of Ce and Ni (CeNi5 alloy) were successfully synthesized, which significantly improved the hydrogen storage performance of magnesium hydride (MgH2). The addition of CeNi5 reduced the initial hydrogen release temperature and increased the hydrogen absorption capacity of MgH2. The merging of Gateway and Spillover effects in one catalyst enhanced the hydrogen storage kinetics of MgH2, suggesting a potential design strategy for highly-effective catalysts in the future.