Enhancement of Catalytic Performance of H-Clinoptilolite in Toluene Abatement from Polluted Air via Controlled Dealumination Method

Abstract

AbstractIn this study, the effect of clinoptilolite dealumination on the total oxidation of toluene was reported for the first time. To avoid excess decrease of catalyst crystallinity, chemical modification of zeolite was carried out using a mild acid like oxalic acid. The catalysts were characterized by XRD, XRF, SEM, BET and TPD analyses. It was found that dealumination resulted in a significant enhancement of toluene conversion when 0.050 M acid oxalic was used for a treatment period of 2 h. Dealumination substantially changed the distribution of the concentration of acid sites of different strength and increased the surface area and porosity, so that the temperature corresponding to the maximum conversion shifts around 50 °C towards lower temperatures (in case of CLP 050). The effect of dealumination on the activity of the zeolite samples and the total oxidation of toluene was discussed in terms of Si/Al ratio, crystallinity, distribution of acid site strength and textural characteristics of the samples.