Hydrogen sorption kinetics of ball-milled MgH2-TTNT nanotubes with different sodium contents
Hydrogen sorption kinetics of ball-milled MgH2-TTNT nanotubes with different sodium contents
复制标题
DOI：
10.1016/j.jallcom.2014.01.244
复制
发表时间：
2014-12
影响因子：
6.2
通讯作者：
P. Jardim;M. Conceição;M. Brum;D. Santos
中科院分区：
文献类型：
--
作者：
P. Jardim;M. Conceição;M. Brum;D. Santos
研究了不同Na含量的TTNT（钛酸盐纳米管）对mgh2吸氢/解吸性能的影响。为了评价钠含量对TTNT氢容量和吸附/解吸动力学的影响，采用两种类型的TTNT，分别是高钠和低钠的水洗TTNT （TTNT- high）和酸洗TTNT （TTNT- low）。采用球磨法制备了MgH2-TTNT复合材料。用DSC分析了含TTNT样品和纯mgh2样品的mgh2相分解。含有TTNT的两种样品的β- mgh2分解温度都比纯mgh2低（且相似），这表明TTNT的存在可以改善氢的解吸。在300°C和350°C下进行氢吸收/解吸动力学测量。在300°C时，两种含TTNT的样品在前5分钟内的吸收动力学均优于纯mgh2。含TTNT的样品在300℃下的解吸动力学明显快于纯MgH2。在350°C时，含有TTNT-High的样品的氢容量和吸收动力学远高于纯MgH2和MgH2+ TTNT-Low。在350°C时，含TTNT的两种样品的氢解吸动力学行为相似，但比纯MgH2的解吸速度快。提出了TTNT在MgH2+ TTNT复合材料吸氢/解吸动力学中的作用机理。
The hydrogen absorption/desorption properties of the MgH2with the addition of TTNT (TiTanate Nanotubes) with different Na contents were studied. In order to evaluate the effect of TTNT Na content on hydrogen capacity and absorption/desorption kinetics two types of TTNT were used: water washed TTNT (TTNT-High) and acid washed TTNT (TTNT-Low) with high and low Na content, respectively. The MgH2-TTNT composites were prepared by ball milling. The MgH2phases decomposition for the two samples containing TTNT and for pure MgH2after milling was evaluated using DSC. β-MgH2temperatures of decomposition are lower (and similar) for both samples containing TTNT than for pure MgH2indicating that the presence of TTNT can improve the hydrogen desorption. Hydrogen absorption/desorption kinetics measurements were performed at 300 and 350 °C. At 300 °C both samples containing TTNT showed better absorption kinetics compared to pure MgH2in the first 5 min. The desorption kinetics at 300 °C of samples containing TTNT was significantly faster than of pure MgH2. At 350 °C the hydrogen capacity and absorption kinetics of samples containing TTNT-High are much higher than for pure MgH2and MgH2+ TTNT-Low. The hydrogen desorption kinetics behavior at 350 °C are similar for both samples containing TTNT but faster than for pure MgH2. A mechanism for the role of TTNT in the hydrogen absorption/desorption kinetics of MgH2+ TTNT composites is proposed.