Quantum chemical mechanism of heterogeneous reaction between trichlorosilane and adsorbed water

We investigated the reaction mechanism of the HCl elimination process of trichlorosilane with adsorbed water in the gas phase by ab initio quantum chemical calculations. The energy barrier in HCl elimination falls to 0.21 kcal/mol with two water molecules. However, in the mechanisms without loss of H2O molecules, the activation energy in successive HCl elimination has been estimated to be at least 33.87 kcal/mol. Our results show that the surface reactions on the steel-use-stainless filter are indispensable for obtaining the result that HCl is generated with a very small amount of H2O in the apparatus.