Catalytic properties of Ni-B and Ni-P ultrafine materials

The ultrafine Ni-B and Ni-P amorphous alloy catalysts were prepared by the chemical reduction method. The catalysts were characterized with respect to ICP-AES, XRD, nitrogen sorption, DSC, SEM, TEM and XPS. Nitrobenzene hydro genation was used to compare their hydrogenation abilities. The different m etalloids of boron and phosphorus bound to the nickel metal for the Ni-B an d Ni-P catalysts result in the distinct different surface area, amorphous s tructure and hydrogenation activity of the catalysts. Ni-B had a larger sur face area than Ni-P. The specific activity per surface area of Ni-P was gre ater than that of Ni-B. The different activities between the Ni-P and Ni-B can be attributed to the difference of the electron density on the nickel m etal; boron donates electrons to the nickel metal and phosphorus accepts el ectrons from the nickel metal. The catalysts were easier to oxidize when th ey were exposed to air. This would result in the lower activity. However, t he activity could be recovered in the reaction process due to the presence of hydrogen in the reaction system. (C) 2000 Society of Chemical Industry.