Catalytic oxidation of aliphatic chlorinated volatile organic compounds over Pt/H-BETA zeolite catalyst under dry and humid conditions

The present study investigated the applicability of noble metal/H-zeolite catalysts for the oxidative decomposition of chlorinated VOCs, and specifically compared the activity and selectivity of Pt/H-BETA with that of an H-BETA for the combustion of dichloromethane and trichloroethylene (1000 ppm in dry and humid air) between 200 and 550 degrees C at a space velocity of 15,000 h(-1). A preliminary study identified the superior catalytic properties of H-BETA as an eventual support for a supported noble metal catalyst compared to other conventional supports such as Al2O3, ZrO2 and SiO2. The primary catalytic property for predicting activity in oxidative decomposition reactions was observed to be the total acidity of the support. Platinum played a major role in influencing the catalytic properties of H-BETA for complete oxidation of the chlorinated volatile organic compounds. Thus, the activity of the resultant Pt/H-BETA catalyst was noticeably enhanced, and the production Of CO2 and Cl-2, the products of CO oxidation and the Deacon reaction, respectively, was largely favoured. The addition of 15,000 ppm of water was found to improve the performance of the Pt/H-BETA catalyst, since the destruction temperatures were significantly lowered and the levels of molecular chlorine and chlorinated by-products were greatly reduced. (c) 2005 Elsevier B.V. All rights reserved.