Synthesis And Properties Of Mesoporous Alumina With Template Method

In this paper,by respectively using PEO-PPO-PEO block copolymer, C₁₁H₂₃COOH and C₁₁H₂₃COONa as template, using aluminum iso-propoxide as precipitator, the meso-structured alumina were synthesized under the method of hydro-thermal.TG,SEM,TEM,IR,XRD and N₂ absorption-desorption were carried out to characterize the as-synthesized materials ,in order to investigate the factors affecting organization,morphology and porous structure of as-synthesized materials of synthesis procedure such as pH values, time of hydrothermal synthesis, crystallization temperature ,calcinations condition and so on.We can say from the experiments that by tuning the amount of P123, we achieved mesoporous alumina with worm-like porous , high surface area, average pore sizes about 15nm, pore volume over 1.0cm³/g,.But its have a slightly wide pore distribution which mostly concentrate on the scale of 5-30nm.The results show that proper amount of template can improve the pore properties of alumina obviously.Compared with using P123 as template ,the obtained samples with C₁₁H₂₃COOH and C₁₁H₂₃COONa as template show the following differences in structure properties.The particles become more homogenous and the porous structure become more regular.The pore diameter and volume reduce in a large extent.Their average pore size are at 6-7nm meanwhile the pore volume reduce to 0.6m³/g The pore distribution become narrow apparently by the rage of 2-11nm.The specific surface area increase in a certain extent and generally reach the value of 400m²/g.The analyst of SEM,TEM,XRD show that samples after calcinations at 600°C are γ-alumina. The samples crystal well when synthesized in autoclave. The pore structure become more normalized and compact.