TiO_(2)@V_(2)O_(5)空心纳米球催化剂增强MgH_(2)体系储氢性能  

Enhancing hydrogen storage properties of MgH_(2) using TiO_(2)@V_(2)O_(5) hollow nanospheres

作　　者：史柯柯 刘木子 刘芳[2] 田甜 王佳丽 陈伟[2] 刘光 宋宇飞[2] 李晋平 Keke Shi;Muzi Liu;Fang Liu;Tian Tian;Jiali Wang;Wei Chen;Guang Liu;Yufei Song;Jinping Li(Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization,College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China;State Key Laboratory of Chemical Resource Engineering,College of Chemistry,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]太原理工大学化学工程与技术学院,气体能源高效清洁利用山西省重点实验室,太原030024 [2]北京化工大学化学学院,化工资源有效利用国家重点实验室,北京100029

出　　处：《科学通报》2024年第14期1923-1933,共11页Chinese Science Bulletin

基　　金：国家自然科学基金(22075196);青海盐湖工业股份有限公司技术开发项目(NZ-H202302118)资助。

摘　　要：氢化镁(MgH_(2))是一种具有高储氢容量(7.6 wt%)的固态储氢材料,但其热力学稳定性高,动力学缓慢,限制了广泛应用.双金属氧化物催化剂对MgH_(2)储氢性能的积极影响已被许多研究者认可.本文采用简便的方法合成了具有纳米空心球结构的TiO_(2)@V_(2)O_(5)双金属氧化物催化剂.添加12 wt%TiO_(2)@V_(2)O_(5)后,MgH_(2)的起始解吸温度显著降低至204℃.在100℃条件下,MgH_(2)在15 min内吸附4.21 wt%的H_(2),在300℃条件下释放6.18 wt%的H_(2),MgH_(2)的活化能从142.78 kJ/mol降低到86.47 kJ/mol.差示扫描量热分析(differential scanning calorimeter,DSC)结果表明,MgH_(2)的氢解吸活化能从197 kJ/mol降低到76.32 kJ/mol.在300℃下循环30次后,储氢量可保持98.49%.研究表明,钛价态的可逆变化和还原金属V的催化作用改善了MgH_(2)动力学及稳定性.The importance of hydrogen energy in the global energy landscape has been growing owing to its several advantages, suchas high energy density, sustainability, renewability, and minimal pollution. The effective utilization of hydrogen energypivots on hydrogen production, storage, and application. Although hydrogen energy offers several advantages, itswidespread adoption is hindered by challenges in developing economical, efficient, and safe hydrogen storagetechnologies. Magnesium-based solid-state storage materials have emerged as a leading contender for hydrogen storageowing to their high storage density and affordability. Magnesium, with its abundant reserves and cost-effectiveness, offerspromising potential for solid hydrogen storage owing to its large hydrogen capacity (volumetric capacity: 110 kg/m3andgravimetric capacity: 7.6 wt%), excellent reversibility, and non-toxicity, attracting considerable research attention in thelast few decades. However, a big challenge in case of magnesium is its strong affinity for hydrogen, which leads to theformation of stable Mg–H bonds with a high decomposition enthalpy for magnesium hydride (MgH_(2)) at 76 kJ/mol H_(2),necessitating desorption at considerably high temperatures (at least 300–400°C) and resulting in slow dehydrogenationkinetics. Thus, developing effective Mg-based hydrogen storage materials is imperative for realizing efficient andeconomical hydrogen storage.Recent studies have focused on enhancing the performance of Mg/MgH_(2) storage systems through alloying, catalyzing,nanosizing, and integrating with complex hydrides. Among these strategies, the incorporation of catalyst additives intoball-milled Mg/MgH_(2) has garnered substantial attention because it enhances hydrogenation/dehydrogenation kinetics andreduces hydrogen sorption temperatures. It is well known that the addition of transition metals as catalysts considerablyimproves the hydrogen sorption kinetics of MgH_(2). While metal oxides, easily reducible to lower-valent metals by reactingwith MgH

关 键 词：氢化镁 二氧化钛 五氧化二钒 动力学性能 循环稳定性 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学]