OH GROUPS AND ACIDIC PROPERTIES OF SAPO-5 AND AIPO_4-5 WITH IR  

作　　者：须沁华 严爱珍 徐开俊 江善根 

机构地区：[1]Department of Chemistry, Nanjing University [2]Department of Chemistry, Nanjing University Centre of Materials Analysis Nanjing University

出　　处：《Science China Chemistry》1989年第7期791-799,共9页中国科学（化学英文版）

基　　金：Project supported by the National Natural Science Foundation of China.

摘　　要：The hydroxyl groups and their acidic properties of AlPO_4-5, SAPO-5 and HZSM-5 havebeen examined by means of IR spectroscopy using the adsorption of D_2O and pyridine asa probe. Four hydroxyl groups characterized by the bands near 3745, 3677, 3630 and 3520cm^(-1) are clearly observed and they are acidic on the sample of SAPO-5. Only two very weakbands at 3677 and 3630 cm^(-1) on AlPO_4-5 could be found. The experiments further indicatethat both of Bronsted and Lewis acid sites are present on the SAPO-5. From NH_3-TPD itis found that the HZSM-5 contains two types of acid sites, medium and strong, while theSAPO-5 contains only one type of medium acid sites. The order of a total amount ofacidity and acid strength is HZSM-5>SAPO-5>AlPO_4-5.The hydroxyl groups and their acidic properties of AlPO₄-5, SAPO-5 and HZSM-5 havebeen examined by means of IR spectroscopy using the adsorption of D₂O and pyridine asa probe. Four hydroxyl groups characterized by the bands near 3745, 3677, 3630 and 3520cm^-1 are clearly observed and they are acidic on the sample of SAPO-5. Only two very weakbands at 3677 and 3630 cm^-1 on AlPO₄-5 could be found. The experiments further indicatethat both of Bronsted and Lewis acid sites are present on the SAPO-5. From NH₃-TPD itis found that the HZSM-5 contains two types of acid sites, medium and strong, while theSAPO-5 contains only one type of medium acid sites. The order of a total amount ofacidity and acid strength is HZSM-5>SAPO-5>AlPO₄-5.

关 键 词：SILICOALUMINOPHOSPHATE molecular SIEVE ACIDITY IR spectroscopy 

分 类 号：O6[理学—化学]