Preparation, characterization, and catalytic behavior of xMO/yNaZSM-5 catalyst for dichlorohydrin dechlorination reaction

A series of loaded CaO or MgO catalysts with NaZSM-5 zeolites as supports were prepared by incipient wetness impregnation and used to catalyze the dechlorination of dichlorohydrin (DCH) to epichlorophydrin (ECH). The resulting prepared catalysts were characterized by X-ray diffraction, N-2 adsorption-desorption, CO2 temperature-programmed desorption, and the Hammett indicator method. The reaction results demonstrated that the MgO/NaZSM-5 catalyst exhibited better catalytic performance compared with the CaO/NaZSM-5. In addition, the effect of different MgO loadings on the activities of as-synthesized catalysts was investigated. Notable, the activity of MgO/NaZSM-5 catalyst increased with the increased loading content of MgO. Based on the obtained characterization for the xMO/yNaZSM-5 catalysts, the increased catalytic activity could be attributed to both the increase of Brunauer-Emmett-Teller values and the increase in base strength resulting from MgO loading onto the NaZSM-5 zeolite. In addition, the calcination temperature of the sample was also an important factor for the DCH dechlorination reaction. Under optimized conditions, 99.8% conversion of 1,3-DCH and 95.5% yield of ECH were achieved using 10MgO/80NaZSM-5 zeolite calcined at 550 degrees C under atmospheric pressure, a reaction temperature of 330 degrees C, weight hourly space velocity of DCH 1.06hr(-1), a nitrogen feed flow rate of 100ml/min and a DCH saturator temperature of 80 degrees C.