Cheng Ying, Zhou Shuhua, Shi Biqing, Dong Bing, Ji Xianbin, Li Siqi, Zhang Wei
Department of Environmental Engineering, Hebei University of Environmental Engineering Qinhuangdao 066102 PR China.
Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University Qinhuangdao 066004 PR China
RSC Adv. 2021 Nov 23;11(60):37677-37683. doi: 10.1039/d1ra06951a.
The effect of the solid solution CeFeZrO, successfully prepared by a hydrothermal synthesis method, on the hydrogen sorption properties of MgH is systemically investigated. The CeFeZrO-modified MgH composite exhibits remarkable hydrogen kinetics properties and thermodynamics behavior compared to those of as-milled MgH, with a reduction in the initial desorption temperature of approximately 82 K. With respect to the hydrogen kinetics, the CeFeZrO-added sample could uptake approximately 5.3 wt% H at 473 K in 2500 s, whereas only 1.5 wt% hydrogen could be absorbed by pristine MgH in the same conditions. Furthermore, about 4.5 wt% of hydrogen could be desorbed by CeFeZrO-doped MgH composite at 623 K, which was 2 wt% higher than the as-milled MgH sample over the same period of time. The decomposition apparent activation energy for MgH-CeFeZrO is reduced to 84.3 kJ mol, which is about 77 kJ mol lower than that of pristine MgH. It is believed that the notable improvement in the hydrogen sorption kinetics is due to the -formed active species of CeH and MgO as well as the abundant oxygen vacancies, which play a vital role in catalyzing the hydrogen sorption performance of MgH.
通过水热合成法成功制备的固溶体CeFeZrO对MgH储氢性能的影响进行了系统研究。与球磨后的MgH相比，CeFeZrO改性的MgH复合材料表现出显著的氢动力学性能和热力学行为，初始脱附温度降低了约82 K。在氢动力学方面，添加CeFeZrO的样品在473 K下2500 s内可吸收约5.3 wt%的H，而在相同条件下原始MgH仅能吸收1.5 wt%的氢。此外，CeFeZrO掺杂的MgH复合材料在623 K下可解吸约4.5 wt%的氢，比球磨后的MgH样品在同一时间段内高2 wt%。MgH-CeFeZrO的分解表观活化能降低至84.3 kJ/mol，比原始MgH低约77 kJ/mol。据信，氢吸附动力学的显著改善归因于形成的活性物种CeH和MgO以及丰富的氧空位，它们在催化MgH的氢吸附性能方面起着至关重要的作用。
