XRD and XPS studies on the ultra-uniform Raney-Ni catalyst prepared from the melt-quenching alloy

We present a novel method for preparing an ultra-uniform Raney-Ni catalyst, which includes melt-quenching, hydrogen treatment and leaching in an alkal i solution. The resultant catalyst shows superior activity in the reaction of cyclohexanone hydrogenation. X-ray diffraction (XRD) and XPS have been e mployed to characterize the catalysts. As demonstrated, the pretreatment wi th hydrogen caused a distinct phase transfer of the Ni-Al alloys, forming m ore of the Ni2Al3 component. In the subsequent leaching process, the Ni2Al3 component shows high activity and the resultant catalyst exhibits high sur face areas and small pores. Moreover, metallic Al in the hydrogen-pretreate d alloy appeared to be leached more easily and thus the aluminium species r emaining on the catalyst surface is aluminium oxide predominantly, which se rves as a matrix to stabilize active Ni species on the surface. Copyright ( C) 2001 John Wiley & Sons, Ltd.