Doping of biogenic Pd catalysts with Au enables dechlorination of diclofenac at environmental conditions

作者：De Corte Simon; Sabbe Tom; Hennebel Tom; Vanhaecke Lynn; De Gusseme Bart; Verstraete Willy; Boon Nico^*

来源：Water Research, 2012, 46(8): 2718-2726.

DOI：10.1016/j.watres.2012.02.036

• Bimetallic catalysts
• Biogenic metals
• Dehalogenation
• Diclofenac

By using the metal reducing capacities of bacteria, Pd nanoparticles can be produced in a sustainable way (%26apos;bio-Pd%26apos;). These bio-Pd nanoparticles can be used as a catalyst in, for example, dehalogenation reactions. However, some halogenated compounds are not efficiently degraded using a bio-Pd catalyst. This study shows that the activity of bio-Pd can be improved by doping with Au(0) (%26apos;bio-Pd/Au%26apos;). In contrast with bio-Pd, bio-Pd/Au could perform the removal of the model pharmaceutical compound diclofenac from an aqueous medium in batch experiments at neutral pH and with H-2 as the hydrogen donor (first order decay constant of 0.078 +/- 0.009 h(-1)). Dehalogenation was for both catalysts the only observed reaction. For bio-Pd/Au, a disproportional increase of catalytic activity was observed with increasing Pd-content of the catalyst. In contrast, when varying the Au-content of the catalyst, a Pd/Au mass ratio of 50/1 showed the highest catalytic activity (first order decay value of 0.52 +/- 0.02 h(-1)). The removal of 6.40 mu g L-1 diclofenac from a wastewater treatment plant effluent using bio-Pd was not possible even after prolonged reaction time. However, by using the most active bio-Pd/Au catalyst, 43.8 +/- 0.5% of the initially present diclofenac could be removed after 24 h. This study shows that doping of bio-Pd nanoparticles with Au(0) can be a promising approach for the reductive treatment of wastewaters containing halogenated contaminants.

• 出版日期2012-5-15