Electrochemical hydrogen storage of aligned multiwalled carbon nanotubes

Hydrogen storage of aligned multi-walled carbon nanotubes (a-MWNTs),non-aligned MWNTs(n-MWNTs) and graphite electrodes are studied by the electro-chemical measurements .The electrodes are prepared by mixing carbon nanotubes (CNTs) copper powder and ptfe binder in a weight ratio of 1:5:3 and compressing the mixture into porous nickel collector,The results show that the electrochemical hydrogen storage capacity of the a-MWNT electrode is up to 1625 mAh/g corresponding to a high hydrogen storage of 5.7 wt% ,which is 10 times that of graphite electrode and is 13 times that of n-MWNT electrode, suggesting that a-MWNTs are promising materials for electrochemical hydrogen storage.     

第一性原理研究锂修饰的类石墨烯碳氮纳米结构的储氢性能

利用基于密度泛函理论的第一性原理方法,研究了锂修饰的类石墨烯碳氮纳米结构的储氢性能.结果表明该体系是一种理想的储氢材料,锂原子通过向衬底转移电荷而带正电,通过静电场的极化作用,每个锂原子可以吸附3个氢分子,其储氢的质量比可达11.5 wt%.氢分子的平均吸附能比较理想,可以实现在室温下可逆的储氢和放氢.     

Interaction of hydrogen with metal nitrides and imides

The pursuit of a clean and healthy environment has stimulated much effort in the development of technologies for the utilization of hydrogen-based energy. A critical issue is the need for practical systems for hydrogen storage, a problem that remains unresolved after several decades of exploration. In this context, the possibility of storing hydrogen in advanced carbon materials has generated considerable interest. But confirmation and a mechanistic understanding of the hydrogen-storage capabilities of these materials still require much work. Our previously published work on hydrogen uptake by alkali-doped carbon nanotubes cannot be reproduced by others. It was realized by us and also demonstrated by Pinkerton et al. that most of the weight gain was due to moisture, which the alkali oxide picked up from the atmosphere. Here we describe a different material system, lithium nitride, which shows potential as a hydrogen storage medium. Lithium nitride is usually employed as an electrode, or as a starting material for the synthesis of binary or ternary nitrides. Using a variety of techniques, we demonstrate that this compound can also reversibly take up large amounts of hydrogen. Although the temperature required to release the hydrogen at usable pressures is too high for practical application of the present material, we suggest that more investigations are needed, as the metal-N-H system could prove to be a promising route to reversible hydrogen storage.     

Ultrafastly activated needle coke as electrode material for supercapacitors

The uniform porous structure makes activated porous carbons (APCs) superior electrode material. Traditionally, APCs are produced by a combination of time-consuming high-temperature heat treatment and activation, with a production time of up to several hours. The produced APCs have relatively low specific surface area (SSA) and porosity. Therefore, the electrochemical performance is poor, which limits its application in high-power energy storage devices. Here, APCs materials are directly synthesized by a high temperature shock (HTS) strategy using needle coke as a precursor. The structure of as-prepared APC is characterized by XRD, SEM and Raman, and electrochemical tests confirmed its good electrochemical performance. In the two-electrode system, the supercapacitor with HTS-APC as the electrode material provides a high energy density of 35 ?Wh kg^?1 and a high power density of 875 ?W ?kg^?1 in EMIMBF₄ ionic liquid. This work is instructive for the rapid synthesis of electrode materials, and also provides guidance for the large-scale application of porous carbon materials.     

介孔活性炭的制备及其高湿储甲烷性能

天然气是一种清洁能源,作为汽车代用燃料以及从天然气开采地到各用户单位之间的运输,都需要有效的存储技术.天然气水合物（NGH）能够降低甲烷存储的成本,而多孔材料孔内生成气体水合物能够有效提高储气密度,本研究目的是合成在孔内能够生成甲烷水合物的低成本高性能吸附剂.首先以农业废弃物玉米芯为原料,采用KOH活化法制备活性炭,其湿储甲烷最优合成条件为：在400,℃炭化30,min,碱炭质量比5∶1、850,℃活化1.0,h合成出C-8高性能活性炭,其孔容达到2.264,cm^3/g,比表面积为2 993,m^2/g,孔径分布主要集中在2～3,nm.合成的C-8是非常好的甲烷湿储吸附剂,在水炭比为3.68时在9.40,MPa下CH4达到最大吸附量为69.66%,是其干燥样品最大吸附量的3.25倍,并可以在较大压力范围内使存储的甲烷提供平稳的放气量,有望作为新型的甲烷水合物存储吸附剂应用于天然气汽车上.     

镁基合金与碳纳米纤维复合储氢材料的制备与性能研究(Ⅰ)--以化学镀Ni碳纳米纤维为前驱物热扩散法合成Mg2Ni-CNFs复合储氢材料

利用金属Mg易热扩散制合金的特性，以化学镀Ni的碳纳米纤维(Ni-CNFs)为前驱物，制备出了Mg-Ni合金与CNFs的复合储氢材料．并测试了其电化学性能，提出了镁基储氢合金与CNFs复合储氢材料的储氢机理．     

碳基储氢材料研究进展

氢能以其可再生性和环境友好性成为未来最具发展潜力的能源载体，储氢技术是氢能应用中的关键问题。本文综述了近年来超级活性炭、石墨纳米纤维、碳纳米纤维和碳纳米管等碳基储氢材料的研究进展，并对该领域未来的研究工作进行了展望。     

Effects of structure and surface properties on carbon nanotubes’ hydrogen storage characteristics

Hydrogen adsorption experiments were carried out in special stainless steel vessels at room temperature (298K) and under 10 MPa using self-synthesized multi-walled carbon nanotubes. In the experiments, carbon nanotubessynthesized by the seeded catalyst method were pretreatedby being soaked in chemical reagents or annealed at hightemperature before they were used to adsorb hydrogen, but their capacity for hydrogen storage was still poor. Carbonnanotubes synthesized by the floating catalyst method were found to be able to adsorb more hydrogen. They have ahydrogen storage capacity of over 4% after they wereannealed at high temperatures, which suggested that theycould be used as a promising material for hydrogen storage.     

活性炭在过氧化氢氧化脱除二苯并噻吩中的催化作用

研究了几种活性炭在过氧化氢氧化二苯并噻吩(DBT)中的催化性能、氧化脱除机理以及碳表面化学对催化性能的影响。考察了活性炭的吸附性能与催化性能以及两者之间的关系、DBT在活性炭上的动态反应活性以及水相pH对其吸附性能和催化性能的影响;并将一种木质活性炭经过3种表面处理,研究了活性炭的表面化学对其催化性能的影响。结果表明:活性炭在过氧化氢氧化DBT中具有较高的催化活性,正辛烷中的DBT转化率可达到81%以上;木质粉末活性炭对DBT的吸附性能优于果壳炭和煤质颗粒活性炭;吸附容量大的活性炭,其催化性能也好;DBT在催化性能高的活性炭作用下的动态反应活性也高;水相pH在低于2的条件下有利于DBT在活性炭上的吸附和催化氧化。DBT的氧化脱除强烈依赖于表面羰基量,是由于表面羰基能加速过氧化氢产生自由基。     

Bimetallic-organic coordination polymers to prepare N-doped hierarchical porous carbon for high performance supercapacitors

Single metal-organic coordination polymers have limited functions as precursors for porous carbon electrode materials.The construction of bimetallic organic coordination polymers can effectively utilize the advantages of each single metal-organic coordination polymer to improve the performance of the derived carbon materials.Herein,High performance nitrogen-doped porous carbon(BC_(Fe–Ni))have been produced by directly carbonizing bimetallic organic coordination polymers formed by 4,4'-bipyridine(BPD)reaction with Fe Cl_3and NiCl_2.The BC_(Fe–Ni) exhibits high nitrogen content(12.66 at%),large specific surface area(1049.51 m~2g~(-1))and hierarchical porous structure,which contributes to an excellent gravimetric specific gravity of 320.5 Fg~(-1)and 108%of specific capacitance retention after 10000 cycles.The BC_(Fe–Ni)assembled symmetrical supercapacitor shows an energy density of 18.3 Wh kg~(-1)at a power density of 350 W kg~(-1).It is expected that the as-prepared N-doped porous carbon derived from bimetallic-organic coordination polymer is a promising electrode material for high performance energy storage devices.     

笼型Li6Si5团簇的结构和储氢性能研究

利用密度泛函M06方法,在6-311+G(d, p)基组水平上对Si_5和Li修饰的Si_5团簇的几何结构和电子性质及储氢性能进行理论计算研究.结果表明, Si_5团簇最低能量构型为笼型结构,纯Si_5团簇不能有效吸附氢分子. Li原子的引入显著改善了Si_5团簇的储氢能力.以六个Li原子穴位修饰Si_5团簇为载体,每个Li原子周围可以有效吸附三个氢分子,其氢分子的平均吸附能为2.395 kcal/mol,储氢密度可达16.617 wt%.合适的吸附能和较高储氢密度表明Li修饰Si_5团簇有望成为理想的储氢材料.     

NaOH为活化剂制备稻壳基高比表面积多孔炭

以氢氧化钠为活化剂制备稻壳基高比表面积多孔炭, 并对其活化机理进行了研究, 制备出比表面积超过2 500 m²/g、 孔径均一、 孔分布窄的多孔炭. 通过控制反应条件可以对多孔炭性能进行控制.     

盐穴在地下能源存储领域的应用及发展

 盐岩具有较低的渗透性、良好的蠕变特性及损伤恢复功能。盐穴是能源地下存储的良好介质,广泛应用于天然气、原油、液态碳氢化合物等的存储;也可以进行压缩空气蓄能和氢气存储蓄能,存储转化可再生能源;同时可应用于工业废料、有害废料的处置及二氧化碳封存等。综述了盐穴在地下能源领域的应用情况及基本原理,展望了盐穴的技术发展趋势。阐述了中国盐穴能源储库起步较晚、资源有限、技术难点多、发展与挑战并存的现状。     

Porous graphene: Properties, preparation, and potential applications

Graphene has recently emerged as an important and exciting material.Inspired by its outstanding properties,many researchers have extensively studied graphene-related materials both experimentally and theoretically.Porous graphene is a collection of graphene-related materials with nanopores in the plane.Porous graphene exhibits properties distinct from those of graphene,and it has widespread potential applications in various fields such as gas separation,hydrogen storage,DNA sequencing,and supercapacitors.In this review,we summarize recent progress in studies of the properties,preparation,and potential applications of porous graphene,and show that porous graphene is a promising material with great potential for future development.     

活性炭微波加热制备装置的仿真设计

活性炭在石化、电力、化工、临床医疗、环保等多个行业中广泛应用,其市场需求量也与日俱增.研究表明,相对于传统方法,微波法制备的活性炭具有孔隙结构更发达,比表面积更大,孔隙结构分布更均匀等优势.然而,这些研究都局限于实验室层面,现有的微波加热装置普遍存在热点、热失控和加热效率低下等问题.这严重限制了微波能在活性炭工业制备中的大规模应用.针对上述问题,本文以国内大量存在的竹子为研究对象,提出了一种可用于活性炭制备的微波均匀加热装置设计方案.通过多物理场仿真计算,以原材料的受热均匀性及装置的能量馈入率为考核标准,采用参数扫描分析的方法对装置参数进行了优化,得到了S11参数为-26.81dB,温度场的变异系数为0.2834的加热装置.此外,本文还结合参数扫描过程以及不同算法的运用,验证了该仿真计算的鲁棒性和准确性.该文章的工作对当前的活性炭工业制备装置的设计具有重要指导意义.     

麻炭的制备及其微观结构

以汉麻秆为原料,通过直接炭化、磷酸/氯化锌活化法制备了麻炭。采用扫描电镜(SEM)、液N₂吸附、亚甲基蓝吸附和碘吸附分别对麻炭的微观骨架结构、表面织构、孔分布及吸附性能进行了表征。结果表明,麻炭微观形貌呈现多孔性的骨架结构,由彼此平行且直通的两种管道构成,管与管之间由管壁隔断,管壁本身分布着丰富的微孔,而且三种麻炭样品中均以微孔为主且微孔分布呈多分散性。未经活化处理的麻炭,其孔径主要分布在小于1.3nm的范围内,但其比表面积和孔容较小。磷酸和氯化锌活化的麻炭的比表面积分别达1388m²/g和1691m²/g,两者的孔分布较为相似,除了在小于2nm的范围内均有微孔分布外,还存在2～4nm范围内的中孔分布。麻炭对亚甲基蓝及碘的吸附值随比表面积的增大而增加,氯化锌活化的麻炭对亚甲基蓝和碘的吸附值最大,其次依次为磷酸活化的麻炭和未经活化处理的麻炭。     

Multilayered graphene membrane as an experimental platform to probe nano-confined electrosorption

Multilayered graphene membranes (MGMs) with different packing densities were prepared and used as electrodes for supercapacitors to probe nano-confined electrosorption in porous carbon materials. The electrosorption capacity of MGMs was measured against an increasing operation rate in a series of aqueous solutions of monovalent ions. The nanoconfinement effect was found prominent when the microscopic pore structure of the MGMs was controlled to be comparable to the size of hydrated ions being tested. The electrosorption capacity was found highly dependent on the type of ions. This study highlights the great potential of using easily available and structurally tunable graphene membranes as a model system to investigate fundamental problems relating to energy storage, membrane separation and nanofluidics.     

Magnesium-based materials for hydrogen storage: Recent advances and future perspectives

Hydrogen storage is a real challenge for realizing ＂hydrogen economy＂ that will solve the critical issues of humanity such as energy depletion, air pollution, greenhouse emission and climate change. Recently, tremendous efforts have been devoted to this internationally focused area. Magnesium （Mg） is among the most promising candidates for this purpose and attracts numerous research interests. This paper is aiming at reviewing recent literatures on approaches and progress, the necessity of further research, and future direction to the research of Mg for hydrogen storage.     

正己醇在改性活性炭上的脱附活化能

制备了Ag^ -活性炭、Cu^2 -活性炭、Fe^3 -活性炭、活性炭、Ba^2 -活性炭和Ca^2 -活性炭6种活性炭，推导了脱附活化能的估算模型，并利用程序升温脱附技术测定了正己醇在这6种活性炭上的脱附活化能，结果表明，正己醇在Ag^ -活性炭、Cu^2 -活性炭和Fe^3 -活性炭的脱附活化能高于其在活性炭上的脱附活化能，而它在Ca^2 -活性炭和Ba^2 -活性炭上的脱附活化能低于它在活性炭上的脱附活化能。     

Current Research Progress in Magnesium Borohydride for Hydrogen Storage (A review)

Hydrogen storage in solid-state materials is believed to be a most promising hydrogen-storage technology for high efficiency, low risk and low cost. Mg(BH₄)₂ is regarded as one of most potential materials in hydrogen storage areas in view of its high hydrogen capacities (14.9 ​wt% and 145–147 ​kg ​cm⁻³). However, the drawbacks of Mg(BH₄)₂ including high desorption temperatures (about 250 ​°C–580 ​°C), sluggish kinetics, and poor reversibility make it difficult to be used for onboard hydrogen storage of fuel cell vehicles. A lot of researches on improving the dehydrogenation reaction thermodynamics and kinetics have been done, mainly including: additives or catalysts doping, nanoconfining Mg(BH₄)₂ in nanoporous hosts, forming reactive hydrides systems, multi-cation/anion composites or other derivatives of Mg(BH₄)₂. Some favorable results have been obtained. This review provides an overview of current research progress in magnesium borohydride, including: synthesis methods, crystal structures, decomposition behaviors, as well as emphasized performance improvements for hydrogen storage.