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

Abstract

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 hydrogenation was used to compare their hydrogenation abilities. The different metalloids of boron and phosphorus bound to the nickel metal for the Ni–B and Ni–P catalysts result in the distinct different surface area, amorphous structure and hydrogenation activity of the catalysts. Ni–B had a larger surface area than Ni–P. The specific activity per surface area of Ni–P was greater 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 metal; boron donates electrons to the nickel metal and phosphorus accepts electrons from the nickel metal. The catalysts were easier to oxidize when they were exposed to air. This would result in the lower activity. However, the activity could be recovered in the reaction process due to the presence of hydrogen in the reaction system. © 2000 Society of Chemical Industry