摘要
考察了处理溶液的pH值及水蒸气分压对 β分子筛酸性的影响 ,发现水蒸气处理后 ,样品的酸密度减小 ;随着水蒸气分压的增大 ,样品的酸密度持续降低 ;酸碱性处理时 ,在pH >7的条件下 ,样品的酸密度基本保持不变 ;pH≤ 7的情况下 ,酸密度随pH值的减小一直呈下降的趋势 ;β分子筛经水蒸气处理或酸碱性处理后 ,B酸的相对含量减小 ,说明分子筛表面的B酸经过改性可转化为L酸 .
The effects of pH value and steam pressure of treating solvent on the acidity of β zeolite were investigated. The results show that the acidity density of zeolite decreased after treating with steam. The higher the steam pressure is, the lower the acidity density. When treated with basic solvent, the acidity density of the sample almost remained unchanged; while acidity density decreased with the decrease of pH value when treated with acidic solvent. The relative content of Bronsted acid reduces after treating with steam or acid/base solvent. Bronsted acid of zeolite surface could convert into Lewis acid in the modification process.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2004年第6期913-918,共6页
CIESC Journal
基金
中国石油化工股份有限公司 (No X5 0 10 3 2 )
化工联合国家重点实验室资助项目~~
关键词
Β分子筛
酸性
改性
Acidity
Chemical modification
pH
Steam
