文献类型：期刊文献

英文题名：Theoretical study on the structure transition under the thermal decomposition of MgCl2·H2O

作者：Liu, Zhaoting[1]; Liu, Yuantao[1]; Lu, Guimin[1]; Yu, Jianguo[1]

机构：[1] National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, 200237, China

年份：2020

卷号：139

期号：6

起止页码：3735

外文期刊名：Journal of Thermal Analysis and Calorimetry

收录：EI(收录号：20193507386856)

语种：英文

外文关键词：Density functional theory - High resolution transmission electron microscopy - Hydrolysis - Magnesium compounds - Molecular dynamics - Reaction kinetics - Thermolysis

摘要：Cathodic passivation is mainly caused by the hydrolysis of anhydrous magnesium chloride. However, the phase transition process of magnesium chloride hydrates is still insufficient although it is important in industrial technology. Here, the thermal decomposition processes of MgCl2·H2O have been investigated using molecular dynamics simulations and density functional theory methods. Two kinetic types of reaction pathways were proposed which can be classified as the intramolecular model and intermolecular model. The calculations show that the intermolecular scheme was easier occurred as it provided a lower energy barrier pathway. Moreover, a theoretical structure of the hydrolysis product (MgOHCl) was determined and then modified in consideration of the experimental information. With the detailed orientation relationship between MgOHCl and MgCl2 examined by transmission electron microscopy, MgOHCl structure was confirmed to be an atomic alteration and distorted variant of the MgCl2 structure. These results indicate the validity of structure transition based on the reaction pathway and provide important atomistic-scale insight into product formation in these materials. ? 2019, Akadémiai Kiadó, Budapest, Hungary.