Adsorption and reaction of sulfur dioxide on alumina and sodium-impregnated alumina

Journal Article · Thu May 02 04:00:00 EDT 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp9519225· OSTI ID:249664

Mitchell, M B; Sheinker, V N ^[1]; White, M G ^[2]

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1. Clark Atlanta Univ., GA (United States)
2. Georgia Inst. of Technology, Atlanta, GA (United States)

The adsorption and oxidation of SO{sub 2} on alumina and sodium-impregnated alumina has been examined using thermogravimetric analysis and diffuse reflectance infrared Fourier transform spectroscopy. Sulfur dioxide chemisorbs initially at basic sites to form an adsorbed sulfite, which is quantitatively converted to sulfate on oxidation. It has been observed that at low coverages, nearly 2.6 {mu}mol/m{sup 2}, sodium acts as a promoter for the formation of an adsorbed sulfite and sulfate which have structures similar to those of aluminum sulfite and sulfate, respectively. At higher sodium loadings, a second type of adsorbed SO{sub 2} is formed, similar to sodium sulfite and sulfate. The species with the aluminum sulfate structure appears to be more easily decomposed than does the sodium sulfate species and accounts for the regenerable adsorption capacity. Formation of the sodium sulfate species appears to account for the loss of adsorption capacity as the number of adsorption/regeneration cycles increases. Oxidation of the sulfite form to the sulfate form can occur in the absence of added oxygen, but it is an activated process and begins to occur in measurable amounts at temperatures between 150 and 300{degree}C. Partitioning of adsorbed SO{sub 2} between aluminum and sodium forms is not a function of temperature and depends on only sodium loading. 32 refs., 14 figs., 1 tab.

• DOE Contract Number: FG22-90PC90292; FG22-92MT92017
• OSTI ID: 249664
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 18 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
ADSORPTION
ALUMINIUM OXIDES
CHEMICAL REACTIONS
DOPED MATERIALS
INFRARED SPECTRA
OXIDATION
SODIUM
SODIUM SULFATES
SULFITES
SULFUR DIOXIDE
TEMPERATURE DEPENDENCE
THERMAL GRAVIMETRIC ANALYSIS