摘要
用相同摩尔浓度的硝酸铵,柠檬酸以及柠檬酸铵溶液对Naβ沸石进行改性处理得到Hβ沸石;采用XRD、XRF、FT-IR、27Al MAS NMR和29Si MAS NMR等表征手段进行分析。结果表明,采用含羟基的柠檬酸或柠檬酸铵对Naβ沸石进行改性处理,不但可以提高样品结晶度还可以有效限制骨架铝的脱除;经柠檬酸或柠檬酸铵改性可以使Naβ中的Al(S4R,SiteA)转化成Al(S6R,SiteB),而硝酸铵改性的Naβ沸石中只发现一种骨架四面体;还发现硝酸铵和柠檬酸铵改性Naβ沸石后,少量的骨架铝转化为非骨架铝并存在于孔道内,而经过柠檬酸改性后,这部分非骨架铝被带出孔道。
Naβ was modified by ammonium nitrate, citric acid and ammonium citrate solution. The result showed modification with citrate acid or ammonium citrate solution not only have a higher relative crystallinity than that by ammoniumnitrate, but also can restrict the removal of framework tetrahedral A1. Besides, modification with citric acid or ammonium citrate favors AI（ S4R, SiteA） formating AI（S6R,SiteB）, while only one type of framework tetrahedral A1 was found in Naβ modified by ammonium nitrate. Ammonium nitrate, citric acid and ammonium citrate solution all can turn the part of framework A1 into non framework A1, which the non framework A1 may exist in the cavity in Naβ modified by ammonium nitrate or ammonitml citrate, however which of Naβ modified citric acid are carried out the cavity.
出处
《辽宁化工》
CAS
2008年第1期11-15,共5页
Liaoning Chemical Industry
基金
校科研基金170129
