摘要
固态储氢作为一项安全高效的储氢技术受到越来越高的重视,其中镁基储氢(MgH_(2))材料由于其较高的储氢容量、可实现的完全可逆性以及价格优势,被认为是最具应用潜力的储氢材料之一,但其较高的热力学稳定性以及迟缓的放氢动力学限制了它的进一步发展。碳材料作为MgH_(2)中一种常见的添加剂,在储氢性能改善中起到了不可忽视的作用。对还原氧化石墨烯(rGO)、碳纳米管(CNTs)、金属有机框架(MOFs)化合物衍生的碳材料、碳纳米纤维(CNFs)等碳材料对MgH_(2)体系的改性进行了总结。进一步探索碳材料在MgH_(2)中的作用机制,加强碳材料的纳米限域作用并结合催化剂协同改善MgH_(2)储氢性能是一条非常有效的途径。另外,寻找价格低廉、性能优良的碳材料来代替石墨烯、碳纳米管可以有效降低MgH_(2)中碳材料添加剂的成本。
With the implementation and promotion of the dual carbon goal,efficient and environmentally friendly renewable new energy is the consistent pursuit goal of all countries in the world.Hydrogen energy is a sustainable renewable secondary energy source due to its great advantages of high energy,abundant reserves,clean and pollution-free.However,hydrogen has low density and flammable and explosive chemical properties,so the safe and efficient storage of hydrogen is an important guarantee for the large-scale use of hydrogen energy.The solid hydrogen storage is to store hydrogen in the form of solid state,which can greatly alleviate the safety problems of gaseous hydrogen storage and liquid hydrogen storage,and also has the advantages of low cost and easy infrastructure implementation,which is an ideal hydrogen storage method.Among them,magnesium-based hydrogen storage(MgH_(2))materials are considered to be one of the hydrogen storage materials with the most application potential due to their high hydrogen storage capacity,good reversibility and price advantages.However,its good thermodynamic stability and slow hydrogenation kinetics limit its further development.Carbon materials are widely used in MgH_(2) hydrogen storage due to their chemical stability,high specific surface area,and good thermal and electrical conductivity,and they can not only be used as a carrier of metal catalyst,but also play a role in constricting and dispersing hydrogen storage materials.The commonly used carbon materials mainly include reduced graphene oxide(rGO),carbon nanotubes(CNTs),metal organic framework(MOFs)compounds-derived carbon materials,carbon nanofibers(CNFs),etc.The application of different carbon materials in the improvement of hydrogen storage performance of MgH_(2) was systematically reviewed,and the future challenges and development trends were discussed in this review.rGO was a two-dimensional carbon atom sheet,arranged in layers,with good mechanical strength,thermal conductivity and electrical conductivity,as a carrier of transition metal compounds(TiO_(2),NiMoO_(4),Ni_(3)Fe,NiCu,etc.)and transition metal catalyst synergistically improve the kinetic performance of MgH_(2),and the cycle performance of hydrogen storage materials was also significantly improved.Hollow structure CNTs had good thermal conductivity and thermal stability,and were also a good magnesium-based hydrogen storage material additive.During dehydrogenation and hydrogenation,CNTs were used as limiting frameworks and catalysts that could accelerate the diffusion of hydrogen and prevent agglomeration of Mg/MgH_(2).The mechanism of catalytic action of CNTs might be related to factors such as incorporation of carbon nanotubes into magnesium particles,high thermal conductivity of carbon nanotubes,or catalytic additives used for nanotube growth.MOFs material had a unique structural pore structure,and through the heat treatment of oxygen-free environment,a variety of pore structures and graphitized carbon materials could be controlled to form porous carbon materials with large specific surface area.The carbon-encapsulated structure formed by carbon material on the surface of MgH_(2) significantly reduces the aggregation of nanoparticles.CNFs could effectively improve the hydrogen absorption and release kinetic performance of MgH_(2),favor thermal conductivity and hydrogen permeability,and prevent particle agglomeration during circulation.Through the study of different forms of carbon nanofibers,it was found that helical CNTs(HCNFs)had better catalytic activity against MgH_(2) than planar carbon nanofibers(PCNFs),and the morphology played a role in improving the hydrogen storage performance of MgH_(2).In addition,g-C_(3)N_(4) tube(TCN),activated carbon(AC),biochar(BC)materials,etc.were also used in hydrogen storage materials.The mechanism studies showed that electron transfer occurred in the π bond from Mg to C,which established the Mg-C bond and weakened the C-C π bond.These interactions changed the hybridization of C from sp^(2) to sp^(3),which helped C(C-H)absorb hydrogen.During hydrogen release,H was released from C-H and electrons were returned to Mg from C,which reversed contribution of electrons weakens the Mg-H bond and enhances the hydrogen release capacity of MgH_(2).In addition,the large amount of carbon sheet edge exposure due to the larger surface area,curved structure and high density of carbon materials also help improve hydrogen storage performance.It was found that carbon materials played a positive role in the improvement of MgH_(2) hydrogen storage performance,especially the improvement of cycle performance.Relying on its own good electrical conductivity,carbon material accelerated the electron transfer during the hydrogen absorption and release reaction,and relied on the high specific surface area to disperse the hydrogen storage material,which played a role in confinement.However,the improvement of MgH_(2) performance by these functions was still very limited,and carbon materials were also needed to combine with metal catalysts to improve the catalytic effect.How to further study the mechanism of action of carbon materials and regulate the confinement effect of carbon materials and the catalytic effect of metal catalysts were the research directions worthy of attention.In addition,carbon materials such as rGO prepared in the laboratory were expensive,and finding low-cost carbon materials could effectively reduce the cost of hydrogen storage materials.
作者
侯全会
汪金辉
熊永莲
易婷
林圣强
杨玺
Hou Quanhui;Wang Jinhui;Xiong Yonglian;Yi Ting;Lin Shengqiang;Yang Xi(School of Automotive Engineering,Yancheng Institute of Technology,Yancheng 224051,China;Yunnan Energy Research Institute Co.,LTD.,Kunming 650299,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2023年第12期1614-1623,共10页
Chinese Journal of Rare Metals
基金
云南省科技厅基础研究专项——面上项目(202101AT070034)资助
关键词
固态储氢
MgH_(2)
储氢性能
碳材料
作用机制
solid hydrogen storage
MgH_(2)
hydrogen storage performance
carbon materials
mechanism of action
作者简介
侯全会(1987-),男,山东济宁人,博士,研究方向:镁基储氢材料的设计及研究,E-mail:hqhdyx66@ycit.edu.cn;通信作者:杨玺,高级工程师,电话:13658831075,E-mail:446840047@qq.com
