Magnesium-based materials are considered as among the most promising candidates for hydrogen storage,owing to their high storage capacity,safety,and reliability.However,a passivation layer easily forms on the surface ...Magnesium-based materials are considered as among the most promising candidates for hydrogen storage,owing to their high storage capacity,safety,and reliability.However,a passivation layer easily forms on the surface of magnesium,which hinders the dissociation and diffusion of hydrogen.High dehydrogenation temperature,sluggish kinetics and activation difficulties hinder their commercial application.Herein,dual-strategy regulation through nickel microalloying and surface catalysis of TiO_(2/)MnO_(2)catalysts has been proposed to obtain more active sites and diffusion channels that promote hydrogen dissociation and transport.Mg8Ni-X(X=None,TiO_(2),and TiO_(2/)MnO_(2))can achieve more than 80%hydrogen absorption without activation.Mg8Ni-5 wt%TiO_(2)/MnO_(2)absorbs hydrogen 5.27 wt%in 30 s at 200℃and desorbs 5.15 wt%in 20 min at 325℃.The activation energy(E_(a))of hydrogen absorption is 52.04kJ/mol.These results are significantly better than those of Mg8Ni and MgH_(2)under the same conditions.The NiTi phase is generated in the course of hydrogenation,and the coexistence of multiple phases and multivalent Ti facilitates the transport of electrons and H.The dual-strategy regulation means of surface catalysis and microalloying is promising for the design of high-capacity fast hydrogen absorbed and desorbed materials without activation.展开更多
基金financially supported by the Yulin Science and Technology Bureau(Grant No.2023-CXY-202)Scientific Research Program Funded by Shaanxi Provincial Education Department(Grant No.23JP008)+1 种基金Key Research and Development Projects of Shaanxi Province(Grant No.2024GX-YBXM-213)National Natural Science Foundation of China(Grant No.52102109)。
文摘Magnesium-based materials are considered as among the most promising candidates for hydrogen storage,owing to their high storage capacity,safety,and reliability.However,a passivation layer easily forms on the surface of magnesium,which hinders the dissociation and diffusion of hydrogen.High dehydrogenation temperature,sluggish kinetics and activation difficulties hinder their commercial application.Herein,dual-strategy regulation through nickel microalloying and surface catalysis of TiO_(2/)MnO_(2)catalysts has been proposed to obtain more active sites and diffusion channels that promote hydrogen dissociation and transport.Mg8Ni-X(X=None,TiO_(2),and TiO_(2/)MnO_(2))can achieve more than 80%hydrogen absorption without activation.Mg8Ni-5 wt%TiO_(2)/MnO_(2)absorbs hydrogen 5.27 wt%in 30 s at 200℃and desorbs 5.15 wt%in 20 min at 325℃.The activation energy(E_(a))of hydrogen absorption is 52.04kJ/mol.These results are significantly better than those of Mg8Ni and MgH_(2)under the same conditions.The NiTi phase is generated in the course of hydrogenation,and the coexistence of multiple phases and multivalent Ti facilitates the transport of electrons and H.The dual-strategy regulation means of surface catalysis and microalloying is promising for the design of high-capacity fast hydrogen absorbed and desorbed materials without activation.
