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PP-III-17ETHYLENE FROM ETHANOL OVER HETEROPOLYACIDINCORPORATED MESOPOROUS CATALYSTSDogu T. 1 , Ciftci A. 1 , Tokay K.C. 1 , Varisli D. 2 , Dogu G. 31 Middle East Technical Univ., Chem. Eng. Dept. Ankara Turkey, tdogu@metu.edu.trl2 Gazi University, Institute of Sciences, Ankara Turkey3 Gazi University, Chem. Eng. Dept. Ankara, TurkeyProduction of petrochemicals [1-3] from a non-petroleum feedstock has attractedsignificant attention of researchers in recent years. Ethylene and diethylether can beproduced by dehydration of ethanol over solid acid catalysts [3,4]. Discovery ofordered mesoporous silicate structured materials [5] started a new research area incatalysis. Heteroplyacids (HPA) are known to have very strong Bronsted acidity andtested as catalysts in number of acid catalyzed reactions. Major disadvantages ofthese materials are their very low surface area and high solubility in polar solvents,which limit their catalytic applications. In the present study, tungstophosphoric acid(TPA) incorporated mesoporous silicate structured catalysts were synthesizedfollowing a one-pot hydrothermal procedure and their ethanol dehydration activitieswere compared with the silicotungstic acid (STA) incorporated mesoporous catalystsprepared in our recent work [6].ExperimentalHeteroplyacid (HPA) incorporated silicate structured mesoporous catalysts weresynthesized following a direct hydrothermal procedure using TEOS andcetyltrimethylammonium bromide as the silica source and the surfactant,respectively. TPA or STA was added to the synthesis solution and hydrothermalsynthesis was achieved in a Teflon lined autoclave. The synthesized material wasthen throughly washed and calcined for the removal of surfactant. Calcinationtemperature was decided from the thermal analysis of the raw materials and FTIRanalysis of the calcined products. Activities of the synthesized materials were testedfor ethanol dehydration in a vapor phase flow reactor. Details of the experimentalsetup were reported elswhere [3-4].Results and DiscussionsXRD analysis indicated well dispersion of HPA within the amorphous silicatelattice of the mesoporous material. EDS and FTIR analysis indicated wellincorporation of TPA or STA into the structure of the catalyst and mild distortion of470