摘要
采用沉淀法、共沉淀法、溶胶凝胶法和改进的溶胶凝胶法制备出TiO2/Al2O3复合载体,并用XRD、TEM、FT-IR和BET等手段对其进行了表征。BET结果表明,共沉淀法和改进的溶胶凝胶法制得的TiO2/Al2O3载体具有较大的比表面积、孔容和较集中的孔分布。XRD结果表明,复合载体经550℃焙烧后,TiO2和Al2O3分别以锐钛矿和-γAl2O3晶型存在,其中沉淀法和改进的溶胶凝胶法制得载体的锐钛矿特征峰宽而尖锐;共沉淀法和溶胶凝胶法制得的载体的锐钛矿特征峰不明显。TEM结果表明,TiO2以纳米级粒子均匀分布在Al2O3表面上,共沉淀法制备出的复合载体中的锐钛型TiO2粒子在-γAl2O3上以单层或亚单层分散;而改进的溶胶凝胶法制备出的复合载体中,锐钛型TiO2和-γAl2O3粒子以更为清晰的橄榄状和絮状形式存在。FT-IR结果表明,4种方法制备出的复合载体的酸性均主要为L酸,仅含微量的B酸。
The TiO2/Al2O3 combined supports were prepared respectively by preprecipitated, coprecipitated, sol-gel and improved sol-gel method, and then characterized by XRD, TEM, FT-IR and BET. The results of BET showed that the TiO2/Al2O3 combined supports prepared by coprecipitated and improved sol-gel method had large surface area, pore volume and marrow pore diameter distribution. XRD profiles illustrated that after calcinated at 550℃, TiO2 was in the form of anatase and λ-Al2O3 in the form of crystal in the combined support, and the TiO2 particles were uniformly dispersed on λ-Al2O3. The TEM photos showed that TiO2 on the surface of λ-Al2O3 was nanometer grain; when prepared by coprecipitated method, the TiO2 uniformly dispersed on λ-Al2O3 with monolayer or sub-monolayer form, but when prepared by improved sol-gel method, anatase TiO2 and λ-Al2O3 particles were in the shape of olive and flocculence. The FT-IR spectra indicated that there were mainly L acid and only a dram of B acid in nano-TiO2/Al2O3 samples.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2005年第6期12-18,共7页
Acta Petrolei Sinica(Petroleum Processing Section)
