储氢材料第一性原理计算的研究进展

综述了第一性原理计算在储氢材料研究中取得的成果和最新的进展。 第一性原理计算在储氢材料研究中的应用主要有以下4个方面： 1）研究纳米结构的储氢性能; 2） 研究储氢材料中掺杂和缺陷的作用及对储氢性能的影响; 3）研究储氢机理; 4）确定氢化物的几何结构以及预测新型储氢材料。 同时展望了第一性原理计算在储氢领域中的应用前景。     

纳米限域的储氢材料

氢能作为洁净、理想的二次能源,已受到世界各国的广泛关注。然而,氢的储存技术仍然是制约氢能商业化应用的关键技术。利用储氢材料进行储氢被认为是一种安全、高效的固态储氢方式。因此,开发新型高容量的储氢材料与储氢技术成为氢能领域研究的热点之一。纳米限域是将材料填充到纳米孔道里,利用材料和纳米孔道的相互作用促进反应的进行,为化学反应提供一个独特的微环境。近年来,纳米限域逐渐发展成为改善储氢材料热力学和动力学的新方法。本文综述了纳米限域的储氢材料的研究进展,从纳米限域的储氢材料制备、储氢性能、反应机理和存在的问题等方面进行讨论,并指出了纳米限域储氢材料的发展趋势。     

纳米储氢合金

作为一种新型的清洁能源,氢能在日益严峻的能源危机中越来越重要。纳米储氢合金因其优异的性能,被认为是下一代重要的储氢材料。本文介绍了储氢合金的原理、储氢合金的动力学和热力学以及各种储氢材料性能。基于储氢合金的最新研究进展,本文综述了提高纳米合金储氢性能的措施、纳米储氢合金的制备方法及其优缺点,进一步探讨了影响纳米合金储氢性能的因素,对储氢合金的进一步发展进行了展望。     

沸石吸附储氢研究进展

沸石类微孔材料作为储氢介质的研究已成为近年来储氢领域中备受关注的热点问题,但对于其储氢机理、储氢容量及其影响因素的文献报道不尽一致。本文从吸附实验测定和理论计算模拟方面综述了各种结构类型沸石的吸附储氢的研究结果。重点分析了沸石的结构类型、硅铝比、阳离子类型及吸附实验条件差异对储氢量的影响,并讨论了超临界吸附理论模型的发展状况,最后探讨了沸石作为储氢材料的可行性和发展方向。     

含Co或Ni的双金属及三金属纳米颗粒的制备方法及其催化制氢性能

常见的氢气储存方法有液态储氢、高压气态储氢、有机化合物储氢、金属氢化物储氢、吸附储氢及液相化学储氢材料储氢等,其中液相化学储氢材料由于具有含氢量高且可按需即时释放氢气的优点,引起了研究人员的广泛关注。选择合适的催化剂催化液相储氢材料制氢已成为一个研究热点。含有Co或Ni的双金属或三金属纳米颗粒是一种极具应用前景的催化剂,具有价格低廉、储量丰富和催化性能优异等众多优点。本文综述了含Co或Ni的双金属或三金属纳米颗粒的制备方法及其催化制氢性能,并提出了其目前研究中存在的问题和未来的发展方向。     

含Co或Ni的双金属及三金属纳米颗粒制备方法及其催化制氢性能

常见的氢气储存方法有液态储氢、高压气态储氢、有机化合物储氢、金属氢化物储氢、吸附储氢及液相化学储氢材料储氢等,其中液相化学储氢材料由于具有含氢量高、且可按时即需释放氢气的优点,引起了研究人员的广泛关注;选择合适的催化剂催化液相储氢材料制氢已成为一个研究热点。含有Co或Ni的双金属或三金属纳米颗粒是一种极具应用前景的催化剂,具有价格低廉、储量丰富和催化性能优异等众多优点。本文综述了含Co或Ni的双金属或三金属纳米颗粒的制备方法及其催化制氢性能,并提出了其目前研究中存在的问题和未来潜在的发展方向。     

纳米镁储氢材料吸放氢动力学性能的研究进展

综述近十年来国内外有关纳米镁储氢材料吸放氢动力学的研究现状和发展趋势.众多研究表明,应用高能球磨法制备纳米镁复合储氢材料,并以过渡金属氧化物为催化剂,或者用ABx型储氢合金与镁复合,都能显著改善镁的吸放氢动力学性能.     

轻金属配位氢化物储氢体系

实现氢能有效利用的关键技术是开发安全、经济、高效的氢能储运体系。在目前所有的储氢技术中,固态材料化学储氢因其储氢密度大、可循环使用、安全方便储运等优势成为人们关注的焦点;配位氢化物储氢材料是现有储氢材料中体积和质量储氢密度最高的储氢材料。其中,具有高储氢密度、储氢性能优良的轻金属配位氢化物储氢材料是配位氢化物储氢领域研究的重点,目前已经取得了大量成果。本文论述了主要轻金属配位氢化物储氢体系的研究进展,包括硼氢化物储氢体系、铝氢化物储氢体系、氨基化物储氢体系等,阐述和总结了其热解反应机理、动力学性能、晶体结构、最新研究现状,最后对该领域的研究方向进行了总结和展望,指出二元或多元复合储氢体系、高效纳米粒子催化剂和储氢反应环境的综合协同效应将会成为储氢领域未来的研究趋势和重要研究方向。     

硼氢化锂储氢材料研究*

车载储氢是推进氢燃料车规模化商业应用的“瓶颈”环节,开发高性能车载储氢材料/技术成为当前能源及材料领域关注的热点。近年来,随着储氢材料领域的不断拓展,以硼氢化锂（LiBH₄）为典型代表的高储量配位金属氢化物日渐成为新兴的储氢材料研究热点。本文从体系成分/反应路径调整、纳米结构调制、阴/阳离子替代及催化体系构建等方面概述了改善LiBH4综合储/放氢性能的最新研究进展,旨在明确配位硼氢化物储氢材料研究中的关键问题及可能的解决途径。     

MgH_2储氢热力学研究进展

近年来,材料和能源领域中高能量密度车载储氢材料的研究和开发吸引了世界各国科技工作者的广泛兴趣.MgH2作为一种相对廉价的固体储氢材料,其理论储氢量高达7.6 wt%,且循环吸放氢性能较好,业已成为储氢材料领域的研究热点.本文着重从热力学的角度,对MgH2储氢材料的近期研究进展,特别是其储氢热力学性能的改进,包括纳米化、复合、催化、限域以及理论计算等方面进行简要综述,旨在明确当今MgH2作为潜在可应用储氢材料的研究重点和未来发展趋势.     

纳米碳管的制备及其在化学电源中的应用

本文介绍了纳米碳管制备技术的最新研究成果，并对其嵌锂行为，储氢及电催化性能进行了重点讨论，纳米碳管作为一种新型的纳米电极材料，有可能在锂离子电池，镍氢电池，燃料电池等化学电源中得到广泛的应用。     

Hydrogen adsorption in carbon nanostructures: comparison of nanotubes, fibers, and coals

Single-walled carbon nanotubes (SWNT) were reported to have record high hydrogen storage capacities at room temperature, indicating an interaction between hydrogen and carbon matrix that is stronger than known before. Here we present a study of the interaction of hydrogen with activated charcoal, carbon nanofibers, and SWNT that disproves these earlier reports. The hydrogen storage capacity of these materials correlates with the surface area of the material, the activated charcoal having the largest. The SWNT appear to have a relatively low accessible surface area due to bundling of the tubes; the hydrogen does not enter the voids between the tubes in the bundles. Pressure-temperature curves were used to estimate the interaction potential, which was found to be 580+/-60 K. Hydrogen gas was adsorbed in amounts up to 2 wt % only at low temperatures. Molecular rotations observed with neutron scattering indicate that molecular hydrogen is present, and no significant difference was found between the hydrogen molecules adsorbed in the different investigated materials. Results from density functional calculations show molecular hydrogen bonding to an aromatic C[bond]C that is present in the materials investigated. The claims of high storage capacities of SWNT related to their characteristic morphology are unjustified.     

Effect of chemical potential on the computer simulation of hydrogen storage in single walled carbon nanotubes

Hydrogen is a kind of clean, sustainable and renewable energy carrier. Of the problems to be solved for the utilization of hydrogen energy, how to store and transport hydrogen has been given high priority on the research agenda. Recently, carbon nanotubes (CNTs) were reported to be very promising candidates for hydrogen uptake[1], which may have possibility to satisfy the benchmark set by the US Department of Energy (DOE) Hydrogen Plan for fuel cell powered vehicles: a gravimetric density …     

有序中孔炭的电化学储氢性能

将蔗糖、聚环氧乙烯-聚环氧丙烯-聚环氧乙烯三嵌段共聚物和硅源构成的复合物进行预炭化、炭化和除硅处理合成出有序中孔炭, 采用XRD、TEM、HRTEM和N2吸脱附等手段对其进行表征, 并将有序中孔炭制成电极开展恒流充放电储氢性能研究. 结果显示, 具有较高比表面积(720 m2·g-1)和孔容(0.86 cm3·g-1)的有序中孔炭材料的电化学储氢容量为70.1 mAh·g-1, 高于具有相对较低比表面积(610 m2·g-1)和孔容(0.66 cm3·g-1)的有序中孔炭储氢容量(64.1 mAh·g-1). 通过与单壁碳纳米管电极(25.9 mAh·g-1)的对比, 表明有序中孔炭具有良好的电化学储氢性能和更高的电化学活性.     

纳米钯膜电极的制备、结构表征和特殊反应性能

用循环伏安方法制备纳米钯膜电极,运用扫描隧道显微镜和原位红外光谱等方法研究其结构和反应性能.STM图像表明,制备的纳米钯膜具有特殊的层状结构,纳米级厚度的层状晶体由直径6nm左右的Pd微晶聚集而成.发现当钯膜厚度为几个纳米时,CO的吸附表现出异常红外效应,即红外谱峰反向和红外吸收显著增强(增强因子可达42.6).纳米钯膜电极对氢的反应也具有特殊的性能,与氢向钯晶格扩散吸收过程相比较,氢吸脱附的表面过程成为主要反应.研究结果还指出,纳米钯膜电极的异常红外效应和对氢反应的特殊性能与钯膜厚度密切关联,并可归结为钯膜材料的纳米尺度效应.     

Hydrogen adsorption in defected carbon nanotubes

Recently there has been lot of interest in the development of hydrogen storage in various systems for the large-scale application of fuel cells, mobiles and for automotive uses. Hectic materials research is going on throughout the world with various adsorption mechanisms to increase the storage capacity. It was observed that physisorption proves to be an effective way for this purpose. Some of the materials in this race include graphite, zeolite, carbon fibers and nanotubes. Among all these, the versatile material carbon nanotube (CNT) has a number of favorable points like porous nature, high surface area, hollowness, high stability and light weight, which facilitate the hydrogen adsorption in both outer and inner portions. In this work we have considered armchair (5,5), zig zag (10,0) and chiral tubes (8,2) and (6,4) with and without structural defects to study the physisorption of hydrogen on the surface of carbon nanotubes using DFT calculations. For two different H₂ configurations, adsorption binding energies are estimated both for defect free and defected carbon nanotubes. We could observe larger adsorption energies for the configuration in which the hydrogen molecular axis perpendicular to the hexagonal carbon ring than for parallel to C–C bond configuration corresponding to the defect free nanotubes. For defected tubes the adsorption energies are calculated for various configurations such as molecular axis perpendicular to a defect site octagon and parallel to C–C bond of octagon and another case where the axis perpendicular to hexagon in defected tube. The adsorption binding energy values are compared with defect free case. The results are discussed in detail for hydrogen storage applications.     

氢气在单壁碳纳米管束的吸附的密度泛函研究

作者利用密度泛函理论（DFT）计算了氢气在单壁碳纳米管束（SWNTs)中管内 和管间的吸附。考察了温度,孔径以及压力对吸附的分子数密度,重量百分比,单 位体积储存能力以及超额吸附量的影响。DFT计算发现,较大的孔径有利于氢气在 SWNTs中的吸附且氢气在管隙中的吸附不可忽略。计算表明在77 K和6 MPa时,氢气 在2.719 mm的SWNTs的总的吸附的重量百分比分别可达到13.2 wt%,这约是美国能 源部（DOE）目标值的两倍,而单位体积储存能力在DOE目标值附近,而在300 K和 6 MPa时,氢气在2.719 nm的SWNTs的总的吸附的重量百分比仅为1.5 wt%。通过实 验结果与计算结果的比较表明,密度泛函理论的计算结果支持SWNTs有较高的吸附 储氢能力的实验结论。     

Preparation of multi metal–carbon nanoreactors for adsorption and catalysis

Metal–incorporated composite carbon materials have engendered great progress in the fields of catalysis, energy storage and material science because of their size and chemical and physical properties. In this study, a modern technique was applied for the development of multi metal–carbon nanoreactors (MCNRs) from a pristine carbon cage (CC) using template method with nano silica ball (NSB), pyrolysis fuel oil (PFO) and metal nanocrystals such as gold, copper, nickel, potassium and manganese. The newly prepared Au, Cu, Ni, K and Mn deposited carbon nanoreactors were fully characterized by various analytical techniques. Due to their easy fabrication protocols and broad potential applications, the MCNRs were used successfully for the chemisorptions of hydrogen and ethylene gases alongside the solvent–free heterogeneous catalytic oxidation of a secondary alcohol. The MCNRs have exhibited dynamic adsorption performance and excellent catalytic activity.     

Improving Hydrogen Adsorption Enthalpy Through Coordinatively Unsaturated Cobalt in Porous Polymers

The design and synthesis of a new porous organic polymer (POP) incorporated with cobalt carbonyl complexes through built‐in bipyridinic coordination sites for hydrogen storage are described. A thermal activation process was developed to remove the ligated carbonyl and carbon dioxide in order to expose the cobalt atomically inside of porous structure. Various spectroscopic and physical characterization techniques were used to study the coordinated Co sites and the POP's surface property. Upon thermal activation, this new cobalt‐containing POP showed improved hydrogen uptake capacity and isosteric heat of adsorption.     

Novel and Versatile Cobalt Azobenzene-Based Metal-Organic Framework as Hydrogen Adsorbent

A novel URJC-3 material based on cobalt and 5,5′-(diazene-1,2-diyl)diisophthalate ligand, containing Lewis acid and basic sites, has been synthesized under solvothermal conditions. Compound URJC-3, with polyhedral morphology, crystallizes in the tetragonal and P4₃2₁2 space group, exhibiting a three-dimensional structure with small channels along a and b axes. This material was fully characterized, and its hydrogen adsorption properties were estimated for a wide range of temperatures (77–298 K) and pressures (1–170 bar). The hydrogen storage capacity of URJC-3 is quite high in relation to its moderate surface area, which is probably due to the confinement effect of hydrogen molecules inside its reduced pores of 6 Å, which is close the ionic radii of hydrogen molecules. The storage capacity of this material is not only higher than that of active carbon and purified single-walled carbon nanotubes, but also surpasses the gravimetric hydrogen uptake of most MOF materials.