Heterogeneous photocatalysis of butanol and methyl ethyl ketone—characterization of catalyst and dynamic study

Abstract

New titanium dioxide (TiO2) based catalysts were prepared by impregnating commercial zeolites in pellets form using a sol–gel technique. Characterization was done with chemical analysis, X-Ray diffraction, scanning electron microscopy, and BET measurements, together with volatile organic compounds (VOC) adsorption equilibrium experiments. TiO2 happened to fix on the inert binder leading to a close intimacy of mixing with the zeolites crystallites, without significant modification of support properties. A diffusion cell was used to produce dilute polluted air streams for dynamic experiments, in which adsorption and photodegradation phases were alternatively carried out. Regeneration of adsorbent was evaluated regarding experimental conditions. Through a comparison with the results obtained on impregnated mesoporous borosilicate beads, it was clarified that zeolite supports had no effect on 1-butanol (BuOH) photooxidation mechanisms. Yet, evidence for mass transfer limitation was found, and attributed to intracrystalline diffusion in zeolites.