Dechlorination of trichloroethylene in aqueous solution by noble metal-modified iron

[摘要] Bimetallic particles are extremely interesting in accelerating the dechlorination of chlorinated organics. Four noble metals (Pd, Pt, Ru and An), separately deposited onto the iron surface through a spontaneous redox process. promoted the TCE dechlorination rate, and the catalytic activity of the noble metal followed the order of Pd >> Ru > Pt > Au. This order was found to he dependent on the concentrations of adsorbed atomic hydrogen, indicating that the initial reaction was cathodically controlled. Little difference in the distribution of the chlorinated products for the four catalysts (cis-DCE: 51%; 1,1-DCE: 27%; trans-DCE: 15% and VC: 7%) was observed. The chlorinated by-products accumulated in both Pt/Fe and Au/Fe (10.3% and 2.5% of the transformed TCE, respectively), but did not accumulate in Pd/Fe and Ru/Fe, Ru/Fe was further examined as an economical alternative to Pd/Fe. The 1.5% Ru/Fe was found to completely degrade TCE within 80 min. Considering the expense, the yield of chlorinated products and the lifetime of a reductive material, Ru provides a potential alternative to Pd as a catalyst in practical applications. (C) 2004 Elsevier B.V. All rights reserved.

[发布日期] 2004-12-31

[关键词] bimetallic;zero-valent metal;catalytic dechlorination