The study explores the excellent modification effect of Nb nanocatalyst prepared via surfactant assisted ball milling technique (SABM) on the hydrogen storage properties of MgH2. Optimal catalyst doping concentration was determined by comparing onset decomposi-tion temperature, released hydrogen capacity, and reaction rate for different MgH2–ywt％Nb (y = 0, 3, 5, 7, 9) composites. The MgH2–5wt％Nb composite started releasing hydrogen at 186.7℃ and a total of 7.0wt％ hydrogen was released in the dehydrogenation process. In addition, 5wt％ Nb doped MgH2 also managed to release 4.2wt％ H2 within 14 min at 250℃ and had the ability to absorb 4.0wt％ hydrogen in 30 min at 100℃. Cycling tests revealed that MgH2–5wt％Nb could retain 6.3wt％ H2 storage capacity (89.2％) after 20 cycles. Dehydrogenation and hy-drogenation activation energy values were decreased from 140.51±4.74 and 70.67±2.07 kJ·mol?1 to 90.04±2.83 and 53.46±3.33 kJ·mol?1 after doping MgH2 with Nb, respectively. Microstructure analysis proved that homogeneously distributed NbH acted as active catalytic unit for im-proving the hydrogen storage performance of MgH2. These results indicate SABM can be considered as an option to develop other nanocata-lysts for energy related areas.

Farai Michael Nyahuma;Liuting Zhang;Mengchen Song;Xiong Lu;Beibei Xiao;Jiaguang Zheng;Fuying Wu

School of Energy and Power,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Analysis and Testing Center,Jiangsu University of Science and Technology,Zhenjiang 212003,China

矿物冶金与材料学报

[1]Farai Michael Nyahuma;Liuting Zhang;Mengchen Song;Xiong Lu;Beibei Xiao;Jiaguang Zheng;Fuying Wu-.Significantly improved hydrogen storage behaviors in MgH2 with Nb nanocatalyst)[J].矿物冶金与材料学报,2022(09):1788-1797

SABM,ywt,drogenation,NbH

Significantly,improved,storage,behaviors,MgH2,nanocatalyst,study,explores,excellent,modification,effect,prepared,via,surfactant,assisted,ball,milling,technique,properties,Optimal,doping,concentration,was,determined,by,comparing,onset,decomposi,temperature,released,capacity,reaction,rate,different,composites,5wt,started,releasing,total,0wt,dehydrogenation,process,In,addition,doped,also,managed,2wt,within,had,ability,absorb,Cycling,tests,revealed,that,could,retain,3wt,after,cycles,Dehydrogenation,activation,energy,values,were,decreased,from,kJ,respectively,Microstructure,analysis,homogeneously,distributed,acted,active,catalytic,unit,proving,performance,These,results,indicate,considered,option,develop,other,lysts,related,areas

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