Modification of the surface chemistry of activated carbons

• Type: Article in International Scientific Journal
• Date: 1999

Authors

José Luis Figueiredo (Author) FEUP; Manuel Fernando R Pereira (Author) Other; Freitas, MMA (Author) Other; José Melo Orfão (Author) FEUP

Journal

Title: Carbon

Vol. 37

Pages: 1379-1389

ISSN: 0008-6223

Publisher: Elsevier

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ISI Web of Knowledge - 1933 Citations

ISI Web of Science

Scopus - 2335 Citations

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Other information

Authenticus ID: P-001-5E3

DOI: 10.1016/s0008-6223(98)00333-9

Abstract (EN): A NORIT activated carbon was modified by different chemical and thermal treatments (including oxidation in the gas and liquid phases) in order to obtain materials with different surface properties. Several techniques were used to characterize these materials including nitrogen adsorption, chemical and thermal analyses, XPS, TPD and DRIFTS. The results obtained by TPD agree quantitatively with the elemental and proximate analyses of the oxidized materials, and qualitatively with the observations by DRIFTS. A simple deconvolution method is proposed to analyse the TPD spectra, allowing for the quantitative determination of the amount of each functional group on the surface. A multiple gaussian function has been shown to fit the data adequately, the parameters obtained for each fit matching very well the features observed in the experimentally determined TPD spectra. It is shown that gas phase oxidation of the carbon increases mainly the concentration of hydroxyl and carbonyl surface groups, while oxidations in the liquid phase increase especially the concentration of carboxylic acids.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11