Progress in design of new amorphous alloy catalysts

Three new kinds of Ni-based amorphous alloy catalysts, Raney type Ni-P(R-Ni -P), Ni-Co-B, and Ni-B(P)/SiO2, have been prepared by modification of eithe r the rapid quenching method or chemical reduction. Their amorphous structu res have been determined by XRD, EXAFS, and DSC. Their catalytic activities and selectivities have been measured during the hydrogenation of various o rganic compounds, which demonstrate the great improvement on the catalytic properties in comparison with the corresponding amorphous alloy catalysts p repared by the rapid quenching method or chemical reduction previously repo rted. These new amorphous catalysts also exhibit superior catalytic propert ies over the traditional catalysts, such as Raney Ni, Ni/SiO2, and Pd/C, ma king them possible to be used in real industrial catalysis, The relationshi p between the catalytic properties and the structural properties has been d iscussed according to various characterizations, including ICP, WS, EXAFS, XRD, TPD, TPR, hydrogen adsorption, LR, SEM, and TEM, etc. The higher hydro genation activity of R-Ni-P than the Ni-P amorphous catalyst obtained by ra pid quenching is mainly ascribed to the increase of the surface area due to the skeleton structure; the higher activity of Ni-Co-B than the Ni-B amorp hous catalyst demonstrates a promoting effect of the additive metal(s); whi le the higher thermal stability of supported Ni-P(B) than the corresponding unsupported catalysts can be explained by considering the stabilizing effe ct of the silica support on the amorphous structure. (C) 1999 Elsevier Scie nce B.V. All rights reserved.