MgH2 dehydrogenation properties improved by MnFe2O4 nanoparticles
MgH2 dehydrogenation properties improved by MnFe2O4 nanoparticles
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DOI：
10.1016/j.jpowsour.2013.03.096
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发表时间：
2013-10-01
影响因子：
9.2
通讯作者：
Volinsky, Alex A.
中科院分区：
文献类型：
--
作者：
Li, Ping;Wan, Qi;Volinsky, Alex A.
本文首次研究了纳米MnFe2O4对球磨法制备MgH2脱氢性能的催化作用。MgH2 + 7mol % MnFe2O4的起始脱氢温度为300℃，比MgH2的起始脱氢温度低140℃。等温脱氢动力学表明，在0.1 MPa压力下，在300℃下，7mol % mnfe2o4掺杂样品在1 h内可释放5.05 wt.%的氢，而在相同条件下，MgH2仅释放0.49 wt.%的氢，脱氢效果明显改善。差示扫描量热法和Kissinger解吸动力学分析表明，7mol % mnfe2o4掺杂样品的表观活化能为64.55 kJ mol(-1)，与MgH2相比，表观活化能降低190.34 kJ mol(-1)，低于其他已报道的过渡金属氧化物催化剂掺杂MgH2的表观活化能。x射线衍射和x射线光电子能谱测试表明，Mg2MnO4和fe0.8720相协同作用显著改善了MgH2脱氢性能。(C) 2013 Elsevier B.V.版权所有
The catalytic effects of MnFe2O4 nanoparticles on the dehydrogenation properties of MgH2, prepared by ball milling, are investigated for the first time. The onset dehydrogenation temperature for MgH2 + 7 mol % MnFe2O4 is 300 degrees C, 140 degrees C lower, compared with the as-received MgH2. The isothermal dehydriding kinetics shows that 7 mol% MnFe2O4-doped sample can release 5.05 wt.% hydrogen in 1 h at 300 degrees C under 0.1 MPa pressure, whereas as-received MgH2 releases only 0.49 wt.% hydrogen for the same conditions, indicating significantly improved dehydrogenation. From the differential scanning calorimetry and the Kissinger desorption kinetics analysis, the apparent activation energy of 7 mol% MnFe2O4-doped sample is 64.55 kJ mol(-1), resulting in 190.34 kJ mol(-1) decrease, compared with the as-received MgH2, which is lower than that of MgH2 doped with other reported transition metal oxide catalysts. Based on X-ray diffraction and X-ray photoelectron spectroscopy tests, Mg2MnO4 and Fe0.872O phases together play a synergistic role in remarkably improving MgH2 dehydriding properties. (C) 2013 Elsevier B.V. All rights reserved.