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

【摘要】 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℃,compared with un-doped MgH₂.The MgH₂+9%（mass）Co@NiO composite released 6.6%（mass） hydrogen in 350 s at 315℃ and uptook 5.4%（mass） hydrogen in500 s at 165℃,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·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.更多还原

【Abstract】 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℃,compared with un-doped MgH₂.The MgH₂+9%（mass）Co@NiO composite released 6.6%（mass） hydrogen in 350 s at 315℃ and uptook 5.4%（mass） hydrogen in500 s at 165℃,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·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.更多还原