Abstract |
The paper discusses the development of transition metal oxide (TMO)-zeolite oxidation catalysts to control chlorinated volatile organic compounds (CVOC) air emissions. Research has been initiated to enhance the utility of these catalysts by the development of a sorption-catalyst system. Zeolites with a high Al/Si ratio (e.g., Y-zeolite) provide active acid exchange sites. The exchanged and calcined zeolite is impregnated with the same or different metal and calcined to form the TMO film. These TMO-zeolites provide shape selectivity and three types of active sites: unexchanged HY (Bronsted) acid active sites, highly active exchanged sites, and impregnated TMO sites. They can achieve over 95% destruction efficiency at relatively low temperatures (i.e., 300 to 350C) of a humid, low concentration CVOC, and are very resistive to poisoning. In the sorption-catalyst system, the zeolite first would physically adsorb the CVOC at room temperature. |