USE OF METHANOL AS AN IR MOLECULAR PROBE TO STUDY THE SURFACE CHLORINATION OF CERIA

Citation
A. Badri et al., USE OF METHANOL AS AN IR MOLECULAR PROBE TO STUDY THE SURFACE CHLORINATION OF CERIA, Journal of the Chemical Society. Faraday transactions, 93(11), 1997, pp. 2121-2124
Citations number
16
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
ISSN journal
09565000
Volume
93
Issue
11
Year of publication
1997
Pages
2121 - 2124
Database
ISI
SICI code
0956-5000(1997)93:11<2121:UOMAAI>2.0.ZU;2-7
Abstract
Ceria has been chlorinated either by CCl4 treatment at 473 K or by imp regnation with an aqueous HCl solution and the surface studied by IR s pectroscopy using methanol as a probe. It was shown that methanol was molecularly adsorbed on the CCl4-treated ceria, being H bonded to Cl- surface species and O bonded to reduced Ce3+ surface cations. This ass umes the reductive surface substitution of O2- species by Cl- ions dur ing the CCl4 treatment with the formation of CeOCl species (Ce-III). W ith the HCl-impregnated ceria sample, methanol was either molecularly adsorbed or dissociated into methoxy species, indicating a mainly unre duced (Ce-IV) surface that is homogeneously chlorinated by HCl-chemiso rption. The importance of CeOCl surface species was further evidenced when methanol was adsorbed on a reduced Pd/CeO2 catalyst prepared from the PdCl2 precursor.