摘要
考察了以固体硅胶为硅源、 NaAlO2及α Al2O3· H2O两种铝源、以及不同晶化混合液的 SiO2/Al2O3比（ 15～ 50）对β沸石合成的影响。通过 XRD、 DSC/TGA、 29Si NMR及 ICP研究表明，以 NaAlO2为铝源合成的β沸石更易形成 Si(0Al)、 Si(1Al)、 Si(O－ )配位，且化学 SiO2/Al2O3比与晶化混合液 SiO2/Al2O3比基本一致，以α Al2O3· H2O为铝源合成的β沸石更易形成 Si(0Al)、 Si(O－ )、 Si(2Al)配位，且化学 SiO2/Al2O3比低于晶化混合液的 SiO2/Al2O3比； TGA失重量随β沸石 SiO2/Al2O3比增加而增加， DSC吸热量随β沸石 SiO2/Al2O3增加而减少。
The influence of SiO2/Al2O3 ratio ranging from 15 to 50 and influence ofα Al2O3· H2O and NaAlO2 as aluminium sources on the synthesis of beta zeolite have been systematically studied by using XRD, 29Si NMR and ICP. NaAlO2 as aluminium source in beta zeolite synthesis,Si tends to form Si(0Al), Si(1Al) and Si(O－ ) sites, and the SiO2/Al2O3 ratios in beta zeolite and in gel are found to be consistent.α Al2O3· H2O as aluminium source in beta zeolite synthesis,Si tends to form Si(0Al), Si(O－ ) and Si(2Al) sites, and the SiO2/Al2O3 ratio in beta zeolite is lower than that of in gel. In addition, the process of thermal decomposition of TEA in beta zeolite was discussed using DSC and TGA. Under air flow with high heating rate (20℃· min－ 1), Hofmann degradation reaction mechanism was observed and there are 3～ 4 endotherm peaks on DSC spectra. TGA weight loss and DSC endotherm are related to the SiO2/Al2O3 ratio in synthesized Beta zeolite.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2000年第4期567-572,共6页
Chinese Journal of Inorganic Chemistry
关键词
Β沸石
铝源
硅铝比
热分解
结构
催化剂
β-zeolite aluminum source SiO_2/Al_2O_3 characterization
