Influence of Support on Catalytic Activity of Nano-Ni Catalysts in P-nitrophenol Reduction to P-aminophenol

THE CATALYTIC activities of CaCO3-, TiO2-, Al2O3 - and SiO2- ….. supported Ni catalysts in reduction of p-nitrophenol to p-aminophenol were investigated. The catalysts were prepared by impregnation using a solution of appropriate concentrations of NiCl2 in order to obtain catalysts with 2.5, 5 and 10% nickel. The dried solids were treated with hydrazine hydrate to reduce nickel ions to metallic nickel, on which the reduction of p-nitrophenol takes place. The catalysts were characterized by XRD and SEM before and after conducting the reduction reaction of p-nitrophenol .The results showed that all catalysts contain crystalline nano nickel. The catalysts were active in reduction of p-nitrophenol into p-aminophenol. The activity was in the following order: Ni/ TiO2 > Ni/ CaCO3 > Ni/ SiO2> Ni/ Al2O3, i.e. the activity was decreased with increasing the acidity of the supports.