Studies on alumina supported Pd-Fe bimetallic catalysts prepared by deposition-precipitation method for hydrodechlorination of chlorobenzene

The gas phase catalytic hydrodechlorination (HDC) of chlorobenzene was investigated over alumina supported Pd-Fe bimetallic catalysts. A series of Pd-Fe/Al2O3 catalysts with various Fe loadings were prepared by deposition-precipitation (DP) method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (TPR), temperature programmed desorption of H-2 (TPD) and pulse CO chemisorption. XPS and TPR analyses suggested the formation of Pdn+ species when the catalysts were prepared by DP method. The TPR results also revealed that, the addition of small amounts of Fe as second metal to Pd/Al2O3 preferentially stabilized the lower oxidation state of Pd. The addition of Fe to Pd/Al2O3 improves the stability of the catalyst during the hydrodechlorination of chlorobenzene as compared to monometallic Pd catalyst. The high activity and stability of bimetallic Pd-Fe catalysts can be attributed to the formation of active Pdn+ species at the interfaces of Pd-O-Fe. (C) 2009 Published by Elsevier B.V.