Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
581942 | Journal of Hazardous Materials | 2009 | 7 Pages |
Abstract
Aqueous solutions of 400-1000Â mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H2PtCl6, Pd(NO3)3 and Rh(NO3)3. Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503Â K in an oxygen partial pressure of 2.0Â MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9Â hâ1 in the wet catalytic processes.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Chang-Mao Hung,