Pore surface fractal analysis of palladium-alumina ceramic membrane using Frenkel-Halsey-Hill (FHH) model
Pore surface fractal analysis of palladium-alumina ceramic membrane using Frenkel-Halsey-Hill (FHH) model
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DOI：
10.1016/j.jcis.2006.05.041
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发表时间：
2006-09-15
影响因子：
9.9
通讯作者：
Mustafa, N. N. N.
中科院分区：
文献类型：
--
作者：
Ahmad, A. L.;Mustafa, N. N. N.
为了提高氧化铝陶瓷膜对H-2的渗透性和选择性，对氧化铝陶瓷膜进行了钯改性。通过溶胶-凝胶法制备了钯-氧化铝陶瓷膜，并在500-1100 ℃的温度范围内对其进行热处理。采用氮气吸附等温线的分形分析方法，研究了不同化学组成（硝酸、PVA和钯）和煅烧过程的钯-氧化铝陶瓷膜孔表面粗糙度的表面分形维数D.采用Frenkel-Halsey-Hill（FHH）模型对钯-氧化铝膜的D值进行了测定。根据FHH模型，在500 ~ 700 ℃范围内，随着煅烧温度的升高，钯-氧化铝膜的D值增大，而在900和1100 ℃煅烧后，膜的D值减小。随着钯浓度从0.5 g Pd/ 100 ml H_2O增加到2 g Pd/ 100 ml H_2O，膜的D值减小，表明膜表面更光滑。加入较高量的PVA和钯，由于孔的不均匀分布，降低了膜的表面分形。然而，当硝酸浓度从1增加到15 M时，D值增加。考察了焙烧温度、PVA配比、钯浓度、酸浓度等对膜比表面积、孔径和孔分布的影响。(c)2006年爱思唯尔公司All rights reserved.
The alumina ceramic membrane has been modified by the addition of palladium in order to improve the H-2 permeability and selectivity. Palladium-alumina ceramic membrane was prepared via a sol-gel method and subjected to thermal treatment in the temperature range 500-1100 degrees C. Fractal analysis from nitrogen adsorption isotherm is used to study the pore surface roughness of palladium-alumina ceramic membrane with different chemical composition (nitric acid, PVA and palladium) and calcinations process in terms of surface fractal dimension, D. Frenkel-Halsey-Hill (FHH) model was used to determine the D value of palladium-alumina membrane. Following FHH model, the D value of palladium-alumina membrane increased as the calcinations temperature increased from 500 to 700 degrees C but decreased after calcined at 900 and 1100 degrees C. With increasing palladium concentration from 0.5 g Pd/ 100 ml H2O to 2 g Pd/ 100 ml H2O, D value of membrane decreased, indicating to the smoother surface. Addition of higher amount of PVA and palladium reduced the surface fractal of the membrane due to the heterogeneous distribution of pores. However, the D value increased when nitric acid concentration was increased from I to 15 M. The effect of calcinations temperature, PVA ratio, palladium and acid concentration on membrane surface area, pore size and pore distribution also studied. (c) 2006 Elsevier Inc. All rights reserved.