Yusnizam Nurul Yasmeen, Ali Nurul Amirah, Sazelee Noratiqah, Ismail Mohammad
Energy Storage Research Group, Faculty of Ocean Engineering Technology and Informatics, Universiti Malaysia Terengganu, Kuala Nerus 21030, Malaysia.
Materials (Basel). 2023 Mar 8;16(6):2178. doi: 10.3390/ma16062178.
Given its significant gravimetric hydrogen capacity advantage, lithium alanate (LiAlH) is regarded as a suitable material for solid-state hydrogen storage. Nevertheless, its outrageous decomposition temperature and slow sorption kinetics hinder its application as a solid-state hydrogen storage material. This research's objective is to investigate how the addition of titanium silicate (TiSiO) altered the dehydrogenation behavior of LiAlH. The LiAlH-10 wt% TiSiO composite dehydrogenation temperatures were lowered to 92 °C (first-step reaction) and 128 °C (second-step reaction). According to dehydrogenation kinetic analysis, the TiSiO-added LiAlH composite was able to liberate more hydrogen (about 6.0 wt%) than the undoped LiAlH composite (less than 1.0 wt%) at 90 °C for 2 h. After the addition of TiSiO, the activation energies for hydrogen to liberate from LiAlH were lowered. Based on the Kissinger equation, the activation energies for hydrogen liberation for the two-step dehydrogenation of post-milled LiAlH were 103 and 115 kJ/mol, respectively. After milling LiAlH with 10 wt% TiSiO, the activation energies were reduced to 68 and 77 kJ/mol, respectively. Additionally, the scanning electron microscopy images demonstrated that the LiAlH particles shrank and barely aggregated when 10 wt% of TiSiO was added. According to the X-ray diffraction results, TiSiO had a significant effect by lowering the decomposition temperature and increasing the rate of dehydrogenation of LiAlH via the new active species of AlTi and Si-containing that formed during the heating process.
鉴于其在重量氢容量方面的显著优势，铝酸锂（LiAlH）被视为一种适用于固态储氢的材料。然而，其过高的分解温度和缓慢的吸附动力学阻碍了它作为固态储氢材料的应用。本研究的目的是探究添加钛硅酸盐（TiSiO）如何改变LiAlH的脱氢行为。LiAlH-10 wt% TiSiO复合材料的脱氢温度降低至92°C（第一步反应）和128°C（第二步反应）。根据脱氢动力学分析，添加TiSiO的LiAlH复合材料在90°C下2小时能够释放比未掺杂的LiAlH复合材料（小于1.0 wt%）更多的氢（约6.0 wt%）。添加TiSiO后，氢从LiAlH中释放的活化能降低。基于基辛格方程，球磨后的LiAlH两步脱氢的氢释放活化能分别为103和115 kJ/mol。在将LiAlH与10 wt% TiSiO球磨后，活化能分别降至68和77 kJ/mol。此外，扫描电子显微镜图像表明，添加10 wt% TiSiO时，LiAlH颗粒收缩且几乎不团聚。根据X射线衍射结果，TiSiO通过加热过程中形成的含AlTi和Si的新活性物种降低LiAlH的分解温度并提高脱氢速率，从而产生显著影响。
