Carbon composite support improving catalytic effect of NbC nanoparticles on the low-temperature hydrogen storage performance of MgH_(2)  

作　　者：Yuxiao Jia Xuancheng Wang Leijie Hu Xuezhang Xiao Shuoqing Zhang Jiahuan He Jiacheng Qi Ling Lv Fen Xu Lixian Sun Lixin Chen 

机构地区：[1]State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China [2]Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province,Hangzhou 310013,China [3]Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials,School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China

出　　处：《Journal of Materials Science & Technology》2023年第19期65-74,共10页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.U20A20237);the Zhejiang Provincial Nat-ural Science Foundation of China (No.LZ21E010002).

摘　　要：Ultrafine carbon-based transition metal compounds have been widely investigated as efficient catalysts for enhancing the hydrogen storage performance of magnesium hydride.In this work,the carbon ther-mal shock method is applied to synthesize the ultrafine carbon-encapsulated NbC nanoparticles with an average grain size of 17.3 nm.The MgH_(2)-10 wt%NbC/C composites show excellent low-temperature hy-drogen storage performance with the onset dehydrogenation temperature of 196.1℃,which is 92.2℃ and 98℃ lower than that of MgH_(2)-10 wt%NbC and undoped MgH_(2),respectively.Specifically,MgH_(2)-10 wt%NbC/C can absorb 6.71 wt%H_(2) at 100℃ within 30 min around and retain almost 100%reversible hydrogen desorption capacity after 10 cycles.For the catalytic mechanism,the electron transfer process between multi-valence Nb cations of in-situ formed NbH x and Mg,H atoms can greatly improve the cyclic de/rehydrogenation kinetics of MgH_(2)-NbC/C.Besides,the enhancement of dehydrogenation kinetics can also be ascribed to MgH_(2) particle refinement by NbC nanoparticles,and destabilization of the Mg-H bond caused by carbon substrate.This investigation not only proves that carbon-encapsulated NbC nanoparti-cles can greatly enhance the hydrogen storage performance of MgH_(2) but provides an idea of preparing carbon-based transition metal carbides as effective catalysts for magnesium-based hydrogen storage ma-terials.

关 键 词：MgH_(2) Carbon-encapsulated NANOPARTICLES Catalyst Kinetics 

分 类 号：TQ426[化学工程] TB383.1[一般工业技术—材料科学与工程]