The adsorption behaviors of Cl2 on TiC (100) surface: A density functional theory study

Abstract

It is important to study the adsorption behavior of Cl2 molecules on the TiC surface and the formation and transfer of reaction products to understand and to regulate the low-temperature chlorination reaction process of carbonized titanium-bearing slag. Based on the first-principles ab initio calculation method of density functional theory (DFT), the adsorption models of Cl2 molecules on the TiC (100) intact surface and the surface with carbon vacancy are established, and the adsorption structures, electronic properties, differential charge density and partial density of states (PDOS) are calculated and analyzed. The formation process and the optimal formation path of the adsorption reaction product are explored. The investigated results indicate that the Cl atoms in the system bonded to the surface Ti atoms are more stable than the structure formed by bonding to the surface C atoms. The electron flow direction is Ti → C and Ti → Cl. In the reaction of TiC with Cl2 molecules, the TiCl3 intermediate is easier to form than the TiCl2 intermediate. The energy barrier to be overcome to form the TiCl3 intermediate is lower and the energy to be supplied is easily met by external conditions. TiCl3 is then further chlorinated to form TiCl4.