Room Temperature Hydrogen Absorption of Mg/MgH2 Catalyzed by BaTiO3
Room Temperature Hydrogen Absorption of Mg/MgH2 Catalyzed by BaTiO3
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BaTiO3 催化 Mg/MgH2 的室温吸氢
DOI：
10.1021/acs.jpcc.1c05560
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发表时间：
2021-09-03
影响因子：
3.7
通讯作者：
Chen, Ping
中科院分区：
文献类型：
--
作者：
Bolarin, Joshua Adedeji;Zhang, Zhao;Chen, Ping
本文旨在提出显着的洞察力的铁电BaTiO 3纳米材料在边界平面上的MgH 2的分离从185 ℃开始的催化行为。机械研磨和增强的电子在BaTiO 3表面的分布之间的协同作用有助于镁在室温下在30 bar下在20 h内显著吸收4.5 wt %的H-2。复合材料在310 ℃下15分钟内释放的H-2类似于5.7重量%，在250 ℃下90分钟内释放的H-2类似于5.1重量%。降低的分解活化能计算为类似于60 kJ/mol，分解焓为72.3 kJ/mol·H-2。该复合材料在300 ℃下在不到120小时的20次循环中可逆地产生了类似于5.7重量%的H-2。详细的实验结果表明，钛在BaTiO 3“111”孪晶界上的+4和+3态的相互作用以及氧空位的形成对改善Mg/MgH 2的吸附动力学和可逆性起着重要作用。同时，BaTiO_3球磨后在Ti-O和Mg周围的钡的+2态的反常铁电特性也被认为通过化学吸附过程略微提高了MgH_2的脱附焓。我们的研究结果使MgH 2更接近实际应用。
This paper seeks to present notable insights into the catalytic behavior of a ferroelectric BaTiO3 nanomaterial at the boundary plane in the separation of MgH2 starting from 185 degrees C. The synergy between mechanical milling and enhanced electronic distribution at the surface of BaTiO3 aided magnesium to a remarkable absorption of 4.5 wt % H-2 at room temperature under 30 bar within 20 h. The composite released H-2 similar to 5.7 wt % in 15 min at 310 degrees C and similar to 5.1 wt % in 90 min at 250 degrees C. The lowered activation energy of decomposition was calculated to be similar to 60 kJ/mol with a decomposition enthalpy of 72.3 kJ/mol-H-2. The composite reversibly produced similar to 5.7 wt % H-2 across 20 cycles in less than 120 h at 300 degrees C. As revealed by detailed experimental results, the interplay between +4 and +3 states of titanium at "111" twin boundaries of BaTiO3, and the formation of oxygen vacancies, play an important role in improving the sorption kinetics and the reversibility of Mg/MgH2. Meanwhile, the anomalous ferroelectric character of the +2 state of barium around Ti-O and Mg after milling of BaTiO3 is also believed to slightly enhance MgH2 desorption enthalpy via a chemisorption process. Our findings have brought MgH2 a few steps closer to practical applications.