The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over Ni/Al2O3 catalyst on alumina support with different particle size. It is found that support particle size has significant influences on physiochemical properties and catalytic activity of the resulting Ni/Al2O3 catalyst, but little influence on the selec-tivity. At a comparable amount of Ni loading, the catalytic activity of Ni/Al2O3 prepared with alumina support of smaller particle size is lower. The reduction behavior of the catalyst is a key factor in determining the catalytic activity of Ni/Al2O3 catalyst. The supported nickel catalyst 10.3Ni/Al2O3-3 improves the life span of the membrane by reducing fouling on the membrane surface compared to nano-sized nickel.
The b-oriented silicalite-1 membrane on the substrate α-Al2O3 pre-coated with a silica-zirconia intermediate layer was synthesized by using in-situ crystallization. The influence of chemical properties of the substrate surface on crystal growth and orientation was investigated. The result indicated that the surface modification by pre-coating a thin film of chitosan was conducive to the formation of b-oriented silicalite-1 membrane with good quality.
