摘要
采用溶胶-凝胶法制备介孔吸附剂SiO2-TiO2,通过N2吸附-脱附等温线和透射电镜对SiO2-TiO2的结构及形貌进行表征,考察钛掺杂硅胶中钛含量对硅胶结构的影响.用动态水蒸气吸附分析仪研究SiO2-TiO2吸附剂对水蒸气的吸附和再生性能,并通过程序升温脱附测试估算了饱和吸附水的脱附活化能;最后采用Frenkel-Halsey-Hill模型分析吸附剂的粗糙程度及孔径分布范围.结果表明,随着钛/硅摩尔比的减小,材料的比表面积增大,孔径分布变窄,平均孔径减小,吸附水的脱附活化能降低,且吸附剂再生温度低,在低相对湿度即30%以下时的水蒸气吸附性能较MCM-41型二氧化硅强.
First, the meso-porous adsorbent SiO2-TiO2 was synthesized via the sol-gel method. Next, its structure and morphology are characterized by using N2 adsorption and desorption isotherms and by means of TEM so as to reveal the influence of the titanium content in the titanium-doped silica gel on the silica gel structure. Then, the water vapor adsorption and regeneration properties of the adsorbent SiO2-TiO2 are investigated by using a dynamic water vapor sorption analyzer （ DVSA）, and the desorption activation energy of water molecules on absorbent was also estimated by a temperature programmed desorption （TPD） test. Finally, the Frenkel-Halsey-Hill （FHH） model is used to analyze the surface roughness and pore size distribution of the adsorbent. The experimental results show that, with the decrease of the titanium-to-silicon molar ratio, the specific surface area of the adsorbent increases with a narrower pore size distribution and a smaller average pore size, and the desorption activation energy of water molecules on absorbent decreases, and that, the adsorbent SiO2-TiO2 is of a lower regeneration temperature, and its water vapor adsorption capacity is greater than that of MCM-41 silica under a low relative humidity of less than 30%.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第9期14-19,共6页
Journal of South China University of Technology(Natural Science Edition)
基金
NSFC-广东省自然科学联合基金资助项目(U1034005)
国家"973"计划项目(2010CB227103)
关键词
介孔吸附剂
二氧化硅
钛掺杂
溶胶-凝胶法
吸附等温线
程序升温脱附
吸附剂再生
meso-porous adsorbent
silica
titanium-doped
sol-gel method
adsorption isotherms
temperature programmed desorption
adsorbent regeneration
