The anionic T_(x)defects of Nb_(2)CT_(x)MXene as the effective catalytically active center for the Mg-based hydrogen storage materials  

作　　者：Xiang Zhou Haotian Guan Heng Lu Yangfan Lu Jianbo Li Jingfeng Wang Yu'an Chen Qian Li Fusheng Pan 

机构地区：[1]College of Materials Science and Engineering,National Engineering Research Center for Magnesium Alloys,Chongqing University,Chongqing 400045,China [2]National Key Laboratory of Advanced Casting Technologies,Chongqing University,Chongqing 400045,China [3]Chongqing Institute of New Energy Storage Materials and Equipment,Chongqing 401135,China

出　　处：《Journal of Magnesium and Alloys》2025年第2期571-582,共12页镁合金学报(英文)

基　　金：supported by Liuchuang Program of Chongqing Municipality(cx2022038);the Fundamental Research Funds for the Central Universities(2022CDJQY-013);the Graduate Research and Innovation Foundation of Chongqing,China(CYB22005).

摘　　要：While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier,hindering further improvement of catalytic activity.A MXene is characterized by rich anionic groups on its surface,significantly affecting electronic and catalytic functionalities.Using Nb_(2)CT_(x)as an example,we herein illustrate the critical role of anionic T_(x)defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials.The hydrogen desorption properties of MgH_(2)can be significantly enhanced by utilizing T_(x)controllable Nb_(2)CT_(x),and it can release 3.57 wt.%hydrogen within 10 min under 240℃with the reduced dehydrogenation activation barrier.It also realized stable de/hydrogenation reactions for at least 50 cycles.DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T_(x)defect density,accelerating the hydrogen dissociation and diffusion processes at the same time.These results demonstrate that the T_(x)defects serve as the effective catalytically active centers of Nb_(2)CT_(x),offering a flexible catalyst design guideline.

关 键 词：Mg-based hydrogen storage materials MXene DEFECTS Scaling relation CATALYSIS 

分 类 号：O643.36[理学—物理化学]