Acid sites on SiO2-Al2O3 monolayer catalysts:: 31P NMR probes of strength and accessibility

被引：22

作者：

Hu, B ^{[1
]}

Gay, ID ^{[1
]}

机构：

[1] Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2001年 / 105卷 / 01期

关键词：

D O I：

10.1021/jp002926z

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：

We have examined the acidic properties of a SiO2-on-Al2O3 monolayer catalyst by P-31 NMR of adsorbed tricyclohexylphosphine and triphenylphosphine. These large probe molecules permit the assessment of steric effects, by comparison with trimethylphosphine, and reveal differences in acid strengths of surface sites. We find that there are significant constraints to accessing Lewis sites, but not Bronsted sites. The concentration of strong Bronsted sites is slightly less than half of the total concentration of Bronsted sites.

引用

页码：217 / 219

页数：3

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