高比表面大中孔拟薄水铝石和γ-Al2O3的制备研究

大中孔γ-Al₂O₃作为重要的催化剂载体、吸附剂和分离材料，尤其对重油和渣油转化催化剂的研制具有十分重要的意义，但传统大中孔γ-Al₂O₃的制备方法往往以牺牲其比表面积为代价。本文分别从控制拟薄水铝石的析出过程和后处理方法以及添加扩孔剂、助烧结剂扩孔等角度出发，评述了近年来国内外高比表面大中孔γ-Al₂O₃及其前驱物拟薄水铝石的制备方法和扩孔机制，这些方法包括pH摆动法、有机溶剂合成法、表面活性剂组装法、微波加热法、水热处理法、有机溶剂置换法、非常规干燥法和扩孔剂或助烧结剂扩孔法等。最后，还对高比表面大中孔拟薄水铝石和γ-Al₂O₃制备方法的发展趋势进行了展望。

Preparation of Macro-Mesostructured Pseudoboehmite and γ-Al2O3 with High Surface Area

As a very important catalyst support, adsorbent and separate material, the preparation of macro-mesostructured γ-Al₂O₃ is very important, especially for catalytic conversion of petroleum heavy cuts and residues. However, while increasing the pore volumes, the surface areas decrease for most conventional preparation methods of macro-mesostructured γ-Al₂O₃. The methods and their mechanisms to prepare macro-mesostructured pseudoboehmite and γ-Al₂O₃ with high surface areas are reviewed in this paper, including controlling the precipitation process of pseudoboehmite, the precipitation processing techniques of the precipitated pseudoboehmite and the introducing pore forming additives or sintering additives. These preparation ways include pH swing method, organic reagent as reaction media, surfactant assembly, microwave-assisted heating, hydrothermal processing of pseudoboehmite or γ-Al₂O₃ directly, displacement water in wet precipitate by organic solvent, unconventional drying method and control of pore structure with pore forming additives or sintering additives. Finally, development trend for preparation techniques of macro-mesostructured pseudoboehmite and γ-Al₂O₃ is also suggested.