Monometallic nano-catalysts for the reduction of perchlorate in water
D.M. Wang, H.Y. Lin and C.P. Huang
University of Delaware, US
nano-catalysts, perchlorate, reduction
Perchlorate removal in a clean, cost-effective and public-acceptable approach is one of the important issues for current drinking water treatment. Catalytic membrane (CM) was prepared by coating monometallic catalysts of the nano-size onto supports by chemical, electrochemical or Chemical Vapor Deposit (CVD) method. The support materials were stainless steel and graphite. Nano-catalysts were made of transitional metals from the first, second and third row in the periodic table. The CM was characterized by surface analysis techniques including SEM, XPS and BET. The CM was used as cathode where the reduction of perchlorate occurred through hydrogen atoms that were generated on the electrode surface. All experiments were performed at ambient conditions. It was found that perchlorate could be reduced by hydrogen atoms in the presence of catalyst. At a maximum perchlorate concentration of 100 mg/L, it is possible to achieve a > 90% removal in 8 h using nano-catalysts such as Sn, Ti, and Co. The rate constants were between 5.1 and 9.6 μM-L-1-hr-1 among the 18 different monometallic nano-catalysts tested. Chloride was the major end product, whereas a small quantity of chlorite was observed in the presence of Co catalyst. Membrane coated with metallic nano-catalysts such as Co, Sn and Ti are among the most promising system for the treatment of perchlorate containing water.
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Nanotech 2006 Conference Program Abstract