DETERMINATION OF INTEGRATED MOLAR EXTINCTION COEFFICIENTS FOR INFRARED-ABSORPTION BANDS OF PYRIDINE ADSORBED ON SOLID ACID CATALYSTS
DETERMINATION OF INTEGRATED MOLAR EXTINCTION COEFFICIENTS FOR INFRARED-ABSORPTION BANDS OF PYRIDINE ADSORBED ON SOLID ACID CATALYSTS
复制标题
DOI：
10.1006/jcat.1993.1145
复制
发表时间：
1993-06-01
影响因子：
7.3
通讯作者：
EMEIS, CA
中科院分区：
文献类型：
--
作者：
EMEIS, CA
测定了吸附在硅基催化剂酸性中心上的吡啶的红外吸收带的积分摩尔消光系数。在150℃下定量投加吡啶气体时，记录了五种沸石和两种无定形硅铝的红外光谱，并假定积分摩尔消光系数不依赖于催化剂或酸中心的强度。结果表明，吡啶在Brnsted酸位上的1545 cmμ1带特征峰为1.67 cm/−摩尔，在Lewis酸位上的1455 cmμ1带特征峰为2.22 cm/−摩尔。95%可信限估计为±15%。随后对数据的分析没有提供任何证据表明积分系数依赖于催化剂或位置的强度。测量结果表明，Brnsted酸位和Lewis酸位与吡啶的反应速率不同。
Integrated molar extinction coefficients were determined for infrared absorption bands of pyridine adsorbed on acid sites in Si/Al-based catalysts. The infrared spectra of five zeolites and two amorphous silica-aluminas were recorded during quantitative dosing of pyridine gas at 150°C. The integrated molar extinction coefficients were calculated assuming that they did not depend on the catalyst or the strength of the acid site. The resulting values were 1.67 cm/μmol for the 1545-cm−1band characteristic of pyridine on a Brønsted acid site and 2.22 cm/μmol for the 1455-cm−1band of pyridine on a Lewis acid site. The 95% confidence limits were estimated at ±15%. Subsequent analysis of the data provided no evidence for a dependence of the integrated coefficients on the catalyst or the strength of the site. The measurements gave indications for differences between the rates of reaction of Brønsted and Lewis acid sites with pyridine.