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 m 2 g -1 . Also, the coordination state of aluminum before and after calcination was analyzed by 27 Al-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%.

Designing Glass Nanocomposites with Nonbridging Oxygen Defects: An Approach to Improve Sodium-Ion Conduction

“…Figure 2 reveals wide-angle XRD (WXRD) patterns of MA and nanocomposites to determine their structural morphology. In Figure 2, the WXRD pattern of MA consists of three 59 In the WXRD patterns of nanocomposites, the absence of any other additional peaks confirms the amorphous feature of these nanocomposites. Moreover, constant peak positions can ascertain the stable structural morphology of these samples.…”

“…Figure reveals wide-angle XRD (WXRD) patterns of MA and nanocomposites to determine their structural morphology. In Figure , the WXRD pattern of MA consists of three diffraction peaks at 2θ = 36.6, 46, and 67° assigned to the diffraction planes (311), (400), and (440) of mesoporous γ-Al 2 O 3 , as indexed in the JCPDS 10-425 powder diffraction file . In the WXRD patterns of nanocomposites, the absence of any other additional peaks confirms the amorphous feature of these nanocomposites.…”