fulltext.study @t Gmail

Infrared spectroscopic study of carbon dioxide adsorption on the surface of cerium–gallium mixed oxides

Paper ID Volume ID Publish Year Pages File Format Full-Text
55583 47058 2012 10 PDF Available
Title
Infrared spectroscopic study of carbon dioxide adsorption on the surface of cerium–gallium mixed oxides
Abstract

In order to modified the acid–base properties of pure cerium dioxide, a series of ceria-based oxides doped with gallium(III) cations (from 5 to 50% mol/mol of Ga) was prepared by co-precipitation in basic aqueous solution followed by calcination at 773 K. N2 physisorption at 77 K showed that mesoporous materials with surface areas between 75 and 104 m2/g were obtained. Ga(III) cations were incorporated into the ceria crystal structure up to a concentration close to 20–25% mol/mol of Ga, as revealed by powder X-ray diffraction analysis. Surface basicity was investigated using CO2 chemisorption by mass spectrometry and in situ infrared spectroscopy. A progressive decrease in the surface basicity in the series of ceria–gallia materials was observed as the Ga content increases. Different carbonate and bicarbonate surface species were identified through their vibrational infrared modes. A remarkable decrease in the surface stability of carbonate species, particularly of the polydentate carbonate groups, was detected, which is correlated to the incorporation of gallium(III) into the ceria lattice.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (224 K)Download as PowerPoint slideHighlights► Mesoporous cerium dioxide doped with gallium(III) in a wide cationic molar range (Ce1−xGaxO2−x/2, with x: 0.05, 0.10, 0.20, 0.25 and 0.50) were synthesized. ► A non-linear decrease of the CO2 uptake was observed as the bulk or surface Ga molar content increased in the Ce–Ga mixed oxides. ► Different surface carbonate species were identified by means of in situ infrared spectroscopy. ► The thermal stability of the carbonaceous species was determined as follows: HCO3− < b-CO3 ∼ m-CO3 < p-CO3. ► All the carbonate groups were less stable on the surface of Ce–Ga mixed oxides.

Keywords
Cerium oxide; Gallium oxide; Carbonate species; Infrared spectroscopy
First Page Preview
Infrared spectroscopic study of carbon dioxide adsorption on the surface of cerium–gallium mixed oxides
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Today - Volume 180, Issue 1, 17 January 2012, Pages 9–18
Authors
, , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us