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

Abstract

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, CO 2 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°C under atmospheric pressure, a reaction temperature of 330°C, weight hourly space velocity of DCH 1.06 hr −1 , a nitrogen feed flow rate of 100 ml/ min and a DCH saturator temperature of 80°C.

Synthesis of epichlorohydrin from 1,3‐dichlorohydrin with solid catalysts using γ‐Al2O3 as carrier material

“…Gas–solid heterogeneous systems are widely investigated and used with solid catalysts to catalyze the cyclization of DCH to ECH . Superior to generally used industrial methods, this process has a shorter reaction process, less amount of by‐products, no discharge of wastewater with lower environmental pollution, easier separation and regeneration of catalysts, and easy control of operating conditions and is more convenient for continuous production, being a production route with broad application prospects.…”