A resonance Raman spectroscopic study of the protonation of 2-(4′-hydroxyazo)-benzoic acid adsorbed on oxide surfaces

The adsorption of 2-(4′-hydroxyazo)-benzoic acid (HABA) on silica–alumina and H-mordenite has been studied by resonance Raman (RR) spectroscopy. The neutral and protonated forms of HABA were modelled by ab initio calculations at the B3LYP/DZ level, enabling calculation of the vibrational spectra of...

Full description

Saved in:
Bibliographic Details
Published in:Vibrational spectroscopy 2003-09, Vol.32 (2), p.225-240
Main Authors: Dines, Trevor J., MacGregor, Louise D., Rochester, Colin H.
Format: Article
Language:English
Subjects:
2-(4′-hydroxyazo)-benzoic acid
Oxides
Raman spectroscopy
Surface acidity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The adsorption of 2-(4′-hydroxyazo)-benzoic acid (HABA) on silica–alumina and H-mordenite has been studied by resonance Raman (RR) spectroscopy. The neutral and protonated forms of HABA were modelled by ab initio calculations at the B3LYP/DZ level, enabling calculation of the vibrational spectra of these species, together with vibrational assignments. Adsorption on both oxide surfaces results in protonation of HABA at Brønsted acidic sites, indicating the presence of Brønsted acidic sites on these oxide surfaces with p K a values ⪢1.0. RR studies of HABA adsorption can provide useful information regarding the nature of surface acidity on oxides which is complementary to that obtained from other probe molecules.
ISSN:0924-2031
1873-3697
DOI:10.1016/S0924-2031(03)00064-X