Synthesis of nanoscale CeAl4 and its high catalytic efficiency for hydrogen storage of sodium alanate

• Published in: Rare metals Vol. 36; no. 2; pp. 77 - 85
• Main Authors: Sun, Jian, Xiao, Xue-Zhang, Zheng, Ze-Jun, Fan, Xiu-Lin, Xu, Chen-Chen, Liu, Lang-Xia, Li, Shou-Quan, Chen, Li-Xin
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 01.02.2017
• Subjects: ate系统; Biomaterials; Chemistry and Materials Science; Energy; Materials Engineering; Materials Science; Metallic Materials; NaAlH4; Nanoscale Science and Technology; Physical Chemistry; 储氢; 催化效率; 反应动力学; 直接合成; 纳米铝; 钠; NaAlH; Hydrogen storage; Complex hydride; Nanoscale CeAl; Catalytic mechanism
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-016-0743-2

Nanoscale CeAl4 was directly synthesized by the thermal reaction between CeH2 and nano-aluminum at300℃.Then nano CeAl4-doped sodium alanate（NaAlH4）was synthesized by ball milling NaH/Al with 0.04CeAl4under hydrogen atmosphere at room temperature,and the catalytic efficiency of nanoscale CeAl4 for hydrogen storage of NaAlH4 was systematically investigated.It is shown that CeAl4 can effectively improve the dehydrogenation properties of sodium alanate system.The 0.04CeAl4-doped NaAlH4 system starts to release hydrogen below 80℃,completes dehydrogenation within 10 min at 170℃,and exhibits good cycling de/hydrogenation kinetics at relatively lower temperature（100-140℃）.Apparent activation energy of the dehydrogenation of NaAlH4 can be effectively reduced by addition of CeAl4,resulting in the decrease in desorption temperatures.Moreover,by analyzing the reaction kinetics of nano CeAl4-doped NaAlH4sample,both of the decomposition steps are conformed to a two-dimensional phase-boundary growth mechanism.The mechanistic investigations gained here can help to understand the de-/rehydrogenation behaviors of catalyzed complex metal hydride systems.