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

Abstract

The gas phase catalytic hydrodechlorination (HDC) of chlorobenzene was investigated over alumina supported Pd–Fe bimetallic catalysts. A series of Pd–Fe/Al 2O 3 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 Pd n+ 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/Al 2O 3 preferentially stabilized the lower oxidation state of Pd. The addition of Fe to Pd/Al 2O 3 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 Pd n+ species at the interfaces of Pd–O–Fe.