胶溶剂用量对氧化铝载体物化性质的影响

Effect of Peptizator Amount on Alumina Support Physicochemical Properties

关键词:  胶溶剂  氧化铝  载体

Key words:  peptizator  alumina  support

摘要:

以醋酸为胶溶剂,研究了在氧化铝载体成型过程中胶溶剂用量对氧化铝载体的孔结构、压碎强度、表面酸性等物化性质的影响。研究发现,胶溶剂用量对载体的比表面积影响较小;随着胶溶剂用量的增加,载体的孔容、平均孔径、可几孔径逐渐降低;从孔分布情况看,载体中大于20nm的孔含量降低,而小于10nm的孔含量呈上升趋势。加入胶溶剂后氧化铝载体中L酸含量明显降低,随着胶溶剂用量的增加,载体中L酸含量逐渐减少。胶溶剂的加入改变了载体中微粒子的大小和堆积方式以及配位不饱和四面体铝离子数量,从而使氧化铝载体的物化性质发生变化。

Abstract:

Using acetic acid as peptizator,the influence of peptizator amount on the physicochemical properties of alumina support,such as pore structures,crush strength and surface acidity,were studied during alumina supports preparation.The results show that peptizator amount have small effect on the surface area of alumina support.The pore volume,average pore size and the most probable pore size decreased with the increasing of peptizator amount.It had been discovered from pore size distribution that the numbers of pore more than 20nm decreased and pore less than 10nm increased with the increase of peptizator amount.The Lewis acidity amount of alumina support decreased distinctly when peptizator had been added into alumina support,and it decreased slowly with the increase of peptizator amount.Because of the adding of peptizator,the size and stacking mode of agglomerates in alumina support were changed and the number of coordinatively unsaturated surface tetrahedral sites Aluminum(Al) atoms was altered.Then the physicochemical properties of alumina support are changed.