title: Effects of synthetic conditions on the textural structure of pseudo-boehmite.
abstract: Mesoporous alumina with pseudo-boehmite phase was prepared by using the cation-anion double hydrolysis method from mixed aqueous solution of aluminum sulfate and sodium aluminate. The effect of synthetic conditions on the crystal structure and textual properties of pseudo-boehmite was investigated, such as synthetic temperature, pH value and the addition of sodium silicate. With the assistance of characterization techniques, such as X-ray diffraction (XRD), N2 adsorption-desorption isotherms (BET) and (27)Al magic-angle spinning nuclear magnetic resonance (MAS NMR), the relationship between textural properties of the mesoporous alumina samples and their synthetic conditions was discussed. The results displayed that an increase in synthesis temperature promoted the formation of higher crystalline pseudo-boehmite with the increase of its surface area and pore volume. Pure pseudo-boehmite phase could be obtained in the pH value range from 6.0 to 9.0, while bayerite phase occurred when the pH value was over 10.0. The introduction of sodium silicate could greatly improve the pore volume (1.20 cm(3)/g) and surface area (480.2 m(2)/g) of pseudo-boehmite. Interestingly, pure pseudo-boehmite phase was obtained at very high pH value without formation of bayerite phase when sodium silicate was initially added into the aluminum hydroxide colloid.
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: yangyangupc@gmail.com.
authors: Yang
authors: Y
authors: Yang
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: xuyan10032304@163.com.
authors: Yanyan
authors: Y
authors: Xu
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: bzhcat@163.com.
authors: Baozhai
authors: B
authors: Han
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: xubenjing@upc.edu.cn.
authors: Benjing
authors: B
authors: Xu
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: lxmei@upc.edu.cn.
authors: Xinmei
authors: X
authors: Liu
authors: State Key Laboratory for Heavy Oil Processing, Chemical Engineering College, China University of Petroleum, Qingdao 266580, China. Electronic address: zfyancat@upc.edu.cn.
authors: Zifeng
authors: Z
authors: Yan
keywords: Crystallinity; Pore structure; Pseudo-boehmite; Sodium silicate; pH value