Date of Award
University or Center
Clark Atlanta University(CAU)
Professor Mark Mitchell
Diffuse reflectance infrared spectroscopy techniques have been employed to investigate the interaction and decomposition of DMMP alumina supported iron oxide catalysts differing in iron oxide loading. At room temperature, the low loading iron oxide catalysts have shown no significant activity toward the decomposition ofDMMP, and they behave similarly to alumina. For the low loading iron oxide catalysts, all the methyl stretching vibrations were observed and their relative intensities did not change as a function of exposure to DMMP. On the other hand, DMMP adsorbs dissociatively on the high loading iron oxides, 8.5 wt%10 iron and above. It appears that the P-CH3 bond dissociates upon adsorption of DMMP on the high loading supported iron oxide catalysts at room temperature.
DMMP on alumina supported copper catalyst, 4.04 wt"10 Cu, has been observed to adsorb on the metal oxide through the P=O bond to a Lewis acid site. On the surface, adsorbed DMMP has been observed to decompose with loss of both the methoxy methyl groups and the phosphorus-bound methyl groups between 100 and 200'C. All the methyl groups are decomposed above 300 'c and only phosphate complexes are observed on the surface.
Tesfai, Teweldemedhim M., "Adsorption and decomposition of organophosphorus compounds on alumina supported metal oxides" (1998). ETD Collection for AUC Robert W. Woodruff Library. 1540.