Influence of synthesis condition on pore structure of Al pillared clays and supported Pd catalysts for deep oxidation of benzene

Abstract

Alumina pillared clays (Al-PILC) were impregnated with Ce and Pd, and then studied as catalysts in the deep oxidation of benzene of low concentration (130–160 ppm). The influence of synthesis conditions on pore structure of Al-PILC was investigated, and also the relationship between structure of the supports and catalytic properties in benzene oxidation of the catalysts was studied. The supports and catalysts were characterized by X-ray powder diffraction, N 2 adsorption, atomic force microscopy, transmission electron microscopy, and temperature programmed reduction techniques. The results showed that pillaring caused a strong increase in basal spacing ( d 001), surface area, micropore volume ( V mic) and mesopore surface area ( A mes). Doping with Ce on Al-PILC yielded a super structure and a reduction in V mic and A mes. Activity tests showed that optimized synthesis conditions of pillaring solution and doping with Ce can obviously improve the activity of Pd/Al-PILC catalysts. The optimized structure of the supports can strengthen the interaction between CeO 2 and Al-PILC, improve the dispersion of Pd particles and increase the active sites, which enhances the catalytic activity of catalysts for the deep oxidation of low concentration of benzene.