LiH潮解过程的原位拉曼光谱研究

In-Situ Raman Spectroscopic Observation of LiH Hydrolysis

LiH是一种氢密度很大(12 wt%)的轻质量材料,在燃料电池、储氢介质等领域中受到了大量的关注。同时,LiH也是一种很好的中子屏蔽、减速材料,被广泛用于核工业中。然而,LiH与H2O极易发生反应,即使在小于1 ppm的水浓度下,LiH也会被H2O逐渐潮解腐蚀,这严重影响了LiH在核工业中的应用[1]。相反,LiH与H2O反应生成H2的反应在氢能应用领域中具有重要的应用前景。因此,无论从哪个方面,LiH的水解反应都是人们重点研究的对象。众多的研究揭示了LiH水解产物层LiH/Li2O/LiOH/LiOH·H2O的多层结构,但其生长机理仍然存在争议[2]。借助于拉曼光谱,我们对LiH的水解反应进行了初期的研究,如图1和图2所示,原位监测到LiH潮解过程中Li2O、LiOH、Li2CO3的生成。

Lithium hydride(LiH)has numerous applications of fuel cells,hydrogen storage and neutron shielding in nuclear industry.The high reactivity of LiH with H2O even at the H2O concentration less than 1 ppm restricted the application of LiH,while its high H2 production of this hydrolysis reaction attracted much attention to the H2 applications.Therefore,understanding the mechanism of LiH hydrolysis is significant for both of the reasons.Previous studies have revealed the multilayer structure(LiH/Li2O/LiOH/LiOH·H2O)of LiH hydrolysis products.However,the mechanisms of the formation of these layers still under debate.With the help of Raman spectroscopy,we conducted a preliminary study on the hydrolysis reaction of LiH,and monitored in situ the generation of Li2O,LiOH and Li2CO3 during LiH hydrolysis.