Thermal decomposition of 1,1,1-trichloroethane and 1,1-dichloroethene over high surface area alumina

Mass spectrometry and X-ray photoelectron spectroscopy have been used to study the decomposition of 1,1,1-trichloroethane (CH[sub 3]CCl[sub 3]) over high surface area [gamma]-alumina (Al[sub 2]O[sub 3]) in the temperature range 300-1000 K under flow conditions. The dehydrochlorination of CH[sub 3]CCl[sub 3](g) occurs in the temperature range 400-600 K to form 1,1-dichloroethene(g) CH[sub 2]=CCl[sub 2](g) and HCl(g). Above 700 K the CH[sub 2]=CCl[sub 2](g) decomposes to form HCl(g), and carbon was deposited on the Al[sub 2]O[sub 3] surface. No evidence for the production of chloroacetylene or other major gas phase products from CH[sub 2]=CCl[sub 2] was found, indicating that CH[sub 3]CCl[sub 3] dehydrochlorination to adsorbed C and HCl(g) involves a single gas phase intermediate, CH[sub 2]=CCl[sub 2]. 29 refs., 7 figs., 1 tab.