Preparation And Structure-activity Relationship Of Rare Earth-zirconium Mixed Pillared Montmorillonite And Its Application In Supported Catalysts

Volatile organic compounds (VOCs) are one of the most common pollutants emitted by the industrial processes represent a serious environmental problem. Catalytic combustion is one of the most attractive ways for controlling the emission of VOCs. As most reports indicated, the catalyst supports play an important role in the improvement of catalytic activity. Clays, a kind of natural aluminosilicates, are commercially attractive for their lower price compared to some other catalyst supports. Moreover, pillared clays have caught attention as catalysts and catalyst supports for their porosity, reactivity and thermal stability. The addition of second cation such as rare earth element can effectively improve thermal stability and catalytic activity of the pillared clays. The rare earth elements show good catalytic performance and excellent oxygen storage capacity. The catalysts added rare earth element into noble or transition metal showed good catalytic activity, thermal resistance and stability.In the first of this paper, we illustrate the research progress of pillared montmorillonite and mixed metal pillared montmorillonite. Then we introduced the catalysts and supports for controlling the VOCs at present, and forecasted the pillared montmorillonite would be the hopeful catalyst support for dealing with VOCs. At last, we introduced the current situation of rare earth application for catalytic combustion of VOCs. In our study, a new material of zirconium pillared montmorillonite adding with rare earth element was prepared. The structure and catalytic properties of the materials were investigated by means of XRD, TEM, N₂ adsorption-desorption, H2-TPR and so on. The catalytic activity of samples for VOCs (included acetone, toluene and ethyl acetate) oxide reaction was investigated. The better condition and rare earth element were selected out for preparing support. Zirconium and yttrium pillared montmorillonite was the best support. Pd, Co, Fe and Ce were supported on this support by wet impregnation. Then the thermal stability and the catalytic activity of VOCs oxidation over the catalysts with various Co, Fe and Ce content were investigated.Surface properties, pore structure and reducibility of the catalysts were investigated by means of TEM, N₂ adsorption-desorption, H₂-TPR and EDX methods. The results showed Co, Fe and Ce catalysts supported on zirconium and yttrium pillared montmorillonite show the same catalytic activity as noble metal supported catalysts in our experiment.