MOBILITY OF ACIDITY - STUDY OF THE EFFECT OF TEMPERATURE ON ACID-BRIDGED GROUPS IN DEALUMINATED MORDENITE BY IN-SITU IR SPECTROSCOPY

被引：9

作者：

SHEN, JP ^{[1
]}

SUN, T ^{[1
]}

YANG, XW ^{[1
]}

JIANG, DZ ^{[1
]}

MIN, EZ ^{[1
]}

机构：

[1] RES INST PETR PROC,BEIJING 100083,PEOPLES R CHINA

来源：

JOURNAL OF PHYSICAL CHEMISTRY | 1995年 / 99卷 / 32期

关键词：

D O I：

10.1021/j100032a043

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The effect of temperature (300-673 K) on the acid-bridged OH groups of mordenite zeolite with Si/Al ratios between 5.56 and 23.60 was investigated by in situ IR spectroscopy. With increasing temperature, the frequencies of acid-bridged OH groups are shifted to lower values and shape of the spectrum becomes broad. The sensitivity of nu(OH) of the samples to the temperature shows differences (especially above 473 K). Correspondingly, the acidity of the sample shows differences at different temperatures and increases with increasing temperature. Moreover, some weaker acid sites can be made stronger as the temperature rises. In a series of mordenite tested, in the lower temperature region (300-473 K), the order of acidity depends on the conditions of treatment. At higher temperatures (473-673 K), with increasing temperature the acidity of the sample decreases, reaches a minimum (Si/Al = 11.18), and increases again (Si/Al > 11.18).

引用

页码：12332 / 12334

页数：3