Catalytic decomposition of the reactive dye Uniblue A on hematite. Modeling of the reactive surface.
Experimental results from the adsorption and subsequent catalytic combustion of the reactive dye Uniblue A on hematite indicate that this iron oxide can be used as an affordable catalyst for environmental purposes. Uniblue A was adsorbed on hematite and the products of the catalytic oxidation in O2 atmosphere were analyzed by thermal programmed gas-chromatography/mass spectrometry (STDS-GC-MS) analysis. The catalytic combustion of Uniblue A in the presence of hematite led to about 40% conversion of the dye C-content into CO2 at T = 275 degrees C. The activation energy (Ea) for the desorption of CO2 and other polyaromatic hydrocarbons (PAHs) from the hematite surface was determined to be 23.4 kcal mol-1. Identification of the species of Uniblue A in solution and those existing on the hematite surface was carried out in the framework of the generalized two-layer diffuse model. The modeling of the amount of dye absorbed on hematite is in good agreement with the experimental data.
Institute of Physical Chemistry II, EPFL, 1015 Lausanne, Switzerland.
F
F
Herrera
A
A
Lopez
G
G
Mascolo
P
P
Albers
J
J
Kiwi
D000327:Adsorption; D000880:Anthraquinones; D002384:Catalysis; D004396:Coloring Agents; D005290:Ferric Compounds; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D013451:Sulfonic Acids
D000880:Anthraquinones; D004396:Coloring Agents; D005290:Ferric Compounds; D013451:Sulfonic Acids; C000499:ferric oxide; C096133:uniblue A