Trimetallic Pd/Fe/Al particles for catalytic dechlorination of chlorinated organic contaminants.
Zero-valent aluminum based trimetallic particles comprising a combination of catalytically effective amounts (1 wt%) of palladium and zero-valent iron on the aluminum surface were synthesized and tested for the dechlorination of chlorinated methanes in batch reactors. XRD analysis indicated the trimetallic particles present in zero-valent form of all three components. Trimetallic Pd/Fe/Al particles showed a very rapid degradation of carbon tetrachloride leading to a surface normalized rate constant (k(SA)) of approximately 0.03 L/h/m(2), two orders of magnitude higher than that of reported data on zero-valent iron particles under near neutral pH conditions. Hydrocarbons including methane and ethane were the major products that accounted for about 38% and 27% of the carbon tetrachloride lost, respectively. Repetitive addition of carbon tetrachloride showed no loss of activity of Pd/Fe/Al particles for more than 20 cycles. In the absence of palladium, the degradation rate decreased by a factor of 10 suggesting palladium serves as a catalyst. Analysis of anions in the solution revealed that the chloride accounted for 75% of the carbon tetrachloride lost. Metallic ions for aluminum and iron were determined to be about 0.02 and 20 mg/L, respectively at the end of the experiment. No palladium ion was measured.
Huang
Chang-Chieh
CC
Department of Civil and Environmental Engineering, National University of Kaohsiung, Taiwan. d97541002@ntu.edu.tw
Lien
Hsing-Lung
HL
D002251:Carbon Tetrachloride / Q000737:chemistry*; D002384:Catalysis; D008670:Metals / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D008670:Metals; D014874:Water Pollutants, Chemical; D002251:Carbon Tetrachloride