A calorimetric study of the acidity of bulk and silica-supported heteropoly acid H3PW12O40

被引：72

作者：

Kozhevnikova, EF ^{[1
]}

Kozhevnikov, IV ^{[1
]}

机构：

[1] Univ Liverpool, Dept Chem, Liverpool L69 7ZD, Merseyside, England

来源：

JOURNAL OF CATALYSIS | 2004年 / 224卷 / 01期

关键词：

heteropoly acid; H3PW12O40; acid strength; calorimetry;

D O I：

10.1016/j.jcat.2004.03.001

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 acid strength of bulk and SiO2-supported (10-60 wt%) H3PW12O40 (PW) is characterised by differential scanning calorimetry of ammonia adsorption in a gas-solid system and by microcalorimetry of pyridine adsorption in a liquid-solid system (cyclohexane slurry). In both systems, the strength of PW in terms of the heat of adsorption of NH3 or pyridine increases with increasing PW loading on silica, the bulk PW being the strongest acid. The temperature and the heat of NH3 desorption are shown to indicate the acid strength, in full agreement with the heats of NH3 adsorption. Attempts to measure the acidity of PW included in a sol-gel silica matrix have failed due to a large amount of water present in such systems. (C) 2004 Elsevier Inc. All rights reserved.

引用

页码：164 / 169

页数：6

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