Molten LiCl Layer Supported on MgO: Its Possible Role in Enhancing the Oxidative Dehydrogenation of Ethane

Molten lithium chloride, supported on various oxides, promotes the catalytic activity for oxidative dehydrogenation (ODH) of ethane. As a first step toward understanding these systems, we use ab initio molecular dynamics to examine the solvation of ethane, ethylene, oxygen, and water in molten lithium chloride supported on magnesium oxide. Among these molecules, only water dissolves readily in molten LiCl. Possible reactions between O-2 and LiCl(l) have been studied in an effort to identify an intermediate for the ODH mechanism. We found that the formation of LiClO, LiO2, Li2O, LiOH, and Cl-2 requires a substantial increase in the free energy; therefore, we propose that they are not reaction intermediates for ODH. The only process that cannot be ruled out is molecular adsorption of O-2 at the LiCl/MgO interface.