SYNTHESIS OF MESOPOROUS γ-ALUMINA AND ITS CATALYTIC PERFORMANCE IN DICHLOROPROPANOL CYCLIZATION

Abstract

This paper discusses the synthesis and resulting catalytic performance of mesoporous alumina using aluminum isopropoxide as the aluminum source, and synthesized organosiloxane KH560-540 as template. The effects of the hydrothermal conditions, as well as the amount of templating agent at pH values of 5-9 on the structure of the synthesized mesoporous alumina were investigated by nitrogen adsorption-desorption methods, XRD and electron microscopy. Alumina from a rod-like scaffold structure was obtained, and the specific surface area was as high as 508 m2 g-1. Also, the coordination state of aluminum before and after calcination was analyzed by 27Al-NMR spectroscopy. The role of the templating agent in the synthesis process was determined. The synthesis mechanism of mesoporous alumina prepared by a KH560-540 template was also proposed. The acidity of samples that were synthesized by different templating agents were compared to NH3-TPD, and the content of Si in each sample was tested by ICP-OES, the results show that the silicon content has little effect on the acidity of the sample. Finally, we used the synthesized mesoporous alumina to catalyze the cyclization of dichloropropanol to epichlorohydrin, which showed excellent catalytic performance:dichlorohydrin conversion is up to 96% and epichlorohydrin yield of nearly 92%.

Keywords

• mesoporous γ-alumina
• templating agent KH560-540
• catalytic performance