共查询到20条相似文献,搜索用时 15 毫秒
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Harini Gunda Keith G. Ray Leonard E. Klebanoff Chaochao Dun Maxwell A. T. Marple Sichi Li Peter Sharma Raymond W. Friddle Joshua D. Sugar Jonathan L. Snider Robert D. Horton Brendan C. Davis Jeffery M. Chames Yi-Sheng Liu Jinghua Guo Harris E. Mason Jeffrey J. Urban Brandon C. Wood Mark D. Allendorf Kabeer Jasuja Vitalie Stavila 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(6):2205487
Metal boride nanostructures have shown significant promise for hydrogen storage applications. However, the synthesis of nanoscale metal boride particles is challenging because of their high surface energy, strong inter- and intraplanar bonding, and difficult-to-control surface termination. Here, it is demonstrated that mechanochemical exfoliation of magnesium diboride in zirconia produces 3–4 nm ultrathin MgB2 nanosheets (multilayers) in high yield. High-pressure hydrogenation of these multilayers at 70 MPa and 330 °C followed by dehydrogenation at 390 °C reveals a hydrogen capacity of 5.1 wt%, which is ≈50 times larger than the capacity of bulk MgB2 under the same conditions. This enhancement is attributed to the creation of defective sites by ball-milling and incomplete Mg surface coverage in MgB2 multilayers, which disrupts the stable boron–boron ring structure. The density functional theory calculations indicate that the balance of Mg on the MgB2 nanosheet surface changes as the material hydrogenates, as it is energetically favorable to trade a small number of Mg vacancies in Mg(BH4)2 for greater Mg coverage on the MgB2 surface. The exfoliation and creation of ultrathin layers is a promising new direction for 2D metal boride/borohydride research with the potential to achieve high-capacity reversible hydrogen storage at more moderate pressures and temperatures. 相似文献
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高容量储氢材料的研究进展 总被引:6,自引:0,他引:6
氢能是一种理想的二次能源.氢能开发和利用需要解决氢的制取、储存和利用3个问题,而氢的规模储运是现阶段氢能应用的瓶颈.氢的储存方法有高压气态储存、低温液态储存和固态储存等3种.固态储氢材料储氢是通过化学反应或物理吸附将氢气储存于固态材料中,其能量密度高且安全性好,被认为是最有发展前景的一种氖气储存方式.由轻元素构成的轻质高容量储氢材料,如硼氢化物、铝氢化物、氨摹氢化物等,理论储氢容量均达到5%(质量分数)以上,这为固态储氢材料与技术的突破带来了希望.新型储氢材料未来研究的重点将集中于高储氢容量、近室温操作、可控吸/放氢、长寿命的轻金属基氢化物材料与体系. 相似文献
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Functional materials are the key enabling factor in the development of clean energy technologies. Materials of particular interest, which are reviewed herein, are a class of hydrogenous compound having the general formula of M(XHn)m, where M is usually a metal cation and X can be Al, B, C, N, O, transition metal (TM), or a mixture of them, which sets up an iono‐covalent or covalent bonding with H. M(XHn)m is generally termed as a complex hydride by the hydrogen storage community. The rich chemistry between H and B/C/N/O/Al/TM allows complex hydrides of diverse composition and electronic configuration, and thus tunable physical and chemical properties, for applications in hydrogen storage, thermal energy storage, ion conduction in electrochemical devices, and catalysis in fuel processing. The recent progress is reviewed here and strategic approaches for the design and optimization of complex hydrides for the abovementioned applications are highlighted. 相似文献
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Ruyan Wu Xin Zhang Yongfeng Liu Lingchao Zhang Jianjiang Hu Mingxia Gao Hongge Pan 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(32)
Poor reversibility and high desorption temperature restricts the practical use of lithium borohydride (LiBH4) as an advanced hydrogen store. Herein, a LiBH4 composite confined in unique double‐layered carbon nanobowls prepared by a facile melt infiltration process is demonstrated, thanks to powerful capillary effect under 100 bar of H2 pressure. The gradual formation of double‐layered carbon nanobowls is witnessed by transmission electron microscopy (TEM) observation. Benefiting from the nanoconfinement effect and catalytic function of carbon, this composite releases hydrogen from 225 °C and peaks at 353 °C, with a hydrogen release amount up to 10.9 wt%. The peak temperature of dehydriding is lowered by 112 °C compared with bulk LiBH4. More importantly, the composite readily desorbs and absorbs ≈8.5 wt% of H2 at 300 °C and 100 bar H2, showing a significant reversibility of hydrogen storage. Such a high reversible capacity has not ever been observed under the identical conditions. The usable volumetric energy density reaches as high as 82.4 g L?1 with considerable dehydriding kinetics. The findings provide insights in the design and development of nanosized complex hydrides for on‐board applications. 相似文献
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Jue Hu Chengxu Zhang Yizhen Zhang Baomin Yang Qianglong Qi Mingzi Sun Futing Zi Michael K. H. Leung Bolong Huang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(28)
Developing efficient earth‐abundant MoS2 based hydrogen evolution reaction (HER) electrocatalysts is important but challenging due to the sluggish kinetics in alkaline media. Herein, a strategy to fabricate a high‐performance MoS2 based HER electrocatalyst by modulating interface electronic structure via metal oxides is developed. All the heterostructure catalysts present significant improvement of HER electrocatalytic activities, demonstrating a positive role of metal oxides decoration in promoting the rate‐limited water dissociation step for the HER mechanism in alkaline media. The as‐obtained MoS2/Ni2O3H catalyst exhibits a low overpotential of 84 mV at 10 mA cm?2 and small charge‐transfer resistance of 1.5 Ω in 1 m KOH solution. The current density (217 mA cm?2) at the overpotential of 200 mV is about 2 and 24 times higher than that of commercial Pt/C and bare MoS2, respectively. Additionally, these MoS2/metal oxides heterostructure catalysts show outstanding long‐term stability under a harsh chronopotentiometry test. Theoretical calculations reveal the varied sensitivity of 3d‐band in different transition oxides, in which Ni‐3d of Ni2O3H is evidently activated to achieve fast electron transfer for HER as the electron‐depletion center. Both electronic properties and energetic reaction trends confirm the high electroactivity of MoS2/Ni2O3H in the adsorption and dissociation of H2O for highly efficient HER in alkaline media. 相似文献
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Qiming Sun Ning Wang Qiang Xu Jihong Yu 《Advanced materials (Deerfield Beach, Fla.)》2020,32(44):2001818
Hydrogen has emerged as an environmentally attractive fuel and a promising energy carrier for future applications to meet the ever-increasing energy challenges. The safe and efficient storage and release of hydrogen remain a bottleneck for realizing the upcoming hydrogen economy. Hydrogen storage based on liquid-phase chemical hydrogen storage materials is one of the most promising hydrogen storage techniques, which offers considerable potential for large-scale practical applications for its excellent safety, great convenience, and high efficiency. Recently, nanopore-supported metal nanocatalysts have stood out remarkably in boosting the field of liquid-phase chemical hydrogen storage. Herein, the latest research progress in catalytic hydrogen production is summarized, from liquid-phase chemical hydrogen storage materials, such as formic acid, ammonia borane, hydrous hydrazine, and sodium borohydride, by using metal nanocatalysts confined within diverse nanoporous materials, such as metal–organic frameworks, porous carbons, zeolites, mesoporous silica, and porous organic polymers. The state-of-the-art synthetic strategies and advanced characterizations for these nanocatalysts, as well as their catalytic performances in hydrogen generation, are presented. The limitation of each hydrogen storage system and future challenges and opportunities on this subject are also discussed. References in related fields are provided, and more developments and applications to achieve hydrogen energy will be inspired. 相似文献
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Metal Hydride Nanoparticles with Ultrahigh Structural Stability and Hydrogen Storage Activity Derived from Microencapsulated Nanoconfinement 下载免费PDF全文
Jiguang Zhang Yunfeng Zhu Huaijun Lin Yana Liu Yao Zhang Shenyang Li Zhongliang Ma Liquan Li 《Advanced materials (Deerfield Beach, Fla.)》2017,29(24)
Metal hydrides (MHs) have recently been designed for hydrogen sensors, switchable mirrors, rechargeable batteries, and other energy‐storage and conversion‐related applications. The demands of MHs, particular fast hydrogen absorption/desorption kinetics, have brought their sizes to nanoscale. However, the nanostructured MHs generally suffer from surface passivation and low aggregation‐resisting structural stability upon absorption/desorption. This study reports a novel strategy named microencapsulated nanoconfinement to realize local synthesis of nano‐MHs, which possess ultrahigh structural stability and superior desorption kinetics. Monodispersed Mg2NiH4 single crystal nanoparticles (NPs) are in situ encapsulated on the surface of graphene sheets (GS) through facile gas–solid reactions. This well‐defined MgO coating layer with a thickness of ≈3 nm efficiently separates the NPs from each other to prevent aggregation during hydrogen absorption/desorption cycles, leading to excellent thermal and mechanical stability. More interestingly, the MgO layer shows superior gas‐selective permeability to prevent further oxidation of Mg2NiH4 meanwhile accessible for hydrogen absorption/desorption. As a result, an extremely low activation energy (31.2 kJ mol–1) for the dehydrogenation reaction is achieved. This study provides alternative insights into designing nanosized MHs with both excellent hydrogen storage activity and thermal/mechanical stability exempting surface modification by agents. 相似文献
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Alanates, borohydrides, and amides are complex hydrides with high concentration hydrogen that have been actively investigated for materials‐based hydrogen storage on‐board polymer electrolyte membrane fuel cell (PEMFC) vehicle applications. The major challenge is to release hydrogen at fuel cell working temperature range at fast enough rate without simultaneous desorption of fuel cell poisoning impurities. We review recent progress in hydrogen reaction mechanism and schemes for complex hydride hydrogen storage. 相似文献
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用于超高压化学热压缩的稀土储氢合金研究 总被引:2,自引:0,他引:2
具有融氢净化和氢压缩于一体等重要特性的金属氢化物化学热压缩器将成为未来加氢站的核心设备.本文简要介绍了金属氢化物化学热压缩器的工作原理及其特点,针对金属氢化物化学热压缩器对储氢合金的要求,研究开发了一种储氢性能优良、适合于作为化学氢压缩机用的稀土系储氢合金(Mm-Ml-Ca)(Ni-Al)5,测定了合金热力学和动力学性能.利用该合金设计制作了一台氢容量大于1000L、氢压大于40.0 MPa的压缩器样机,在20℃时氢压小于3.0 MPa可吸氢饱和,165℃放氢可得氢压大于40.0 MPa的超高压产品氢.原料氢纯度为98%时,产品氢纯度达到99.9999%.并且对压缩器的热效率进行了计算,其热效率达到21.9%. 相似文献
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纳米金属有机框架材料的储氢性能研究 总被引:2,自引:0,他引:2
采用溶剂热法制备了纳米金属有机框架材料,通过粉末x射线衍射(PXRD)、高分辨透射电镜(HRTEM)、红外光谱(FT-IR)、热重分析(TG)、差示扫描量热法(DSC)和压力-组成-温度测试仪(PCI)等分析和表征手段,获得了该材料结构、形貌、热稳定性和吸附性能等信息.该材料对不同吸附质(如水0.19 g/g和苯0.41 g/g),表现出不同的吸附能力,并具有双亲功能.在77 K,1.5 MPa条件,其储氢量为3.2%(质量分数,下同),包含微孔内填充的高压氢气时为3.4%,包含中孔、微孔内填充的高压氢气时为3.9%. 相似文献
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Yongjin Fang Deyan Luan Xiong Wen Lou 《Advanced materials (Deerfield Beach, Fla.)》2020,32(42):2002976
Sodium-ion batteries (SIBs) have drawn enormous attention in the past few years from both academic and industrial battery communities in view of the fascinating advantages of rich abundance and low cost of sodium resources. Among various electrode materials, mixed metal sulfides (MMSs) stand out as promising negative electrode materials for SIBs considering their superior structural and compositional advantages, such as decent electrochemical reversibility, high electronic conductivity, and rich redox reactions. Here, a summary of some recent developments in the rational design and synthesis of various kinds of MMSs with tailorable architectures, structural/compositional complexity, controllable morphologies, and enhanced electrochemical properties is presented. The effect of structural engineering and compositional design of MMSs on the sodium storage properties is highlighted. It is anticipated that further innovative works on the material design of advanced electrodes for batteries can be inspired. 相似文献