Boosting the hydrogen storage performance of magnesium hydride with metal organic framework-derived Cobalt@Nickel oxide bimetallic catalyst

In this study, a MOF-derived bimetallic Co@NiO catalyst was synthesized and doped into MgH2 to improve the hydrogen desorption and resorption kinetics. The Co@NiO catalyst decreased the onset dehydrogenation temperature of MgH2 by 160 degrees C, compared with un-doped MgH2. The MgH2 + 9% (mass) Co@NiO composite released 6.6% (mass) hydrogen in 350 s at 315 degrees C and uptook 5.4% (mass) hydrogen in 500 s at 165 degrees C, showing greatly accelerated de/rehydrogenation rates. Besides, the desorption activation energy of MgH2 + 9% (mass) Co@NiO was decreased to (93.8 +/- 8.4) kJ center dot mol-1. Noteworthy, symbiotic Mg2NiH4/Mg2CoH5 clusters were in-situ formed from bimetallic precursors and inlaid on MgH2 surface, which are considered as multi-step hydrogen pumps, and provides surface pathways for hydrogen absorption. Meanwhile, the introduced Mg2NiH4/Mg2CoH5 interfaces could provide numerous low energy barrier H diffusion channels, therefore accelerating the hydrogen release and uptake. This research proposes new insights to design high-efficiency bimetallic catalyst for MgH2 hydrogen storage.(c) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

In this study, a MOF-derived bimetallic Co@NiO catalyst was synthesized and doped into MgH2 to enhance the hydrogen desorption and resorption kinetics. The catalyst significantly decreased the onset dehydrogenation temperature and exhibited accelerated hydrogen release and uptake rates. The formation of Mg2NiH4/Mg2CoH5 clusters contributed to the improved hydrogen absorption and provided surface pathways.