Interaction of nitric oxide with the surface of stabilized calcium sulfate
by Benson, R. F.; Blyholder, G. D.
This work explores surface interactions between stabilized gypsum and nitric oxide. Gypsum is a common air-borne mineral particulate that has a potential two-fold relationship to the air pollution problem: as a particulate pollutant and as a catalyst or adsorbent for pollutant gases. Nitric Oxide is found in stack gases and automotive exhausts. Isotherms of nitric oxide adsorbed on stabilized gypsum were studied at 24 degreesC, 0 degreesC, and -78 degreesC. Coverages were related to a monolayer based upon a surface area of 17.0 m(2)/g as determined from a nitrogen adsorption isotherm and the B.E.T. method. Multilayer coverages containing both reversible and irreversible adsorption were observed for nitric oxide adsorbed on stablized hydrated calcium sulfate. An irreversible coverage of 41% at 24 degreesC and 61% at 0 degreesC of the nitrogen monolayer was observed for nitric oxide adsorbed on hydration stabilized gypsum. The heat of adsorption at zero coverage was found to be 80.4 kJ/mol for nitric oxide on stabilized hydrated calcium sulfate for the irreversible adsorption and 7.5 kJ/mol for the reversible adsorption.
- Journal
- Journal of Environmental Science and Health, Part A-Toxic Hazardous Substances and Environmental Engineering
- Volume
- 36
- Issue
- 2
- Year
- 2001
- Start Page
- 141-152
- URL
- https://dx.doi.org/10.1081/ese-100102613
- ISBN/ISSN
- 1532-4117; 1093-4529
- DOI
- 10.1081/ese-100102613