Structure and catalytic properties of Cu-Ni bimetallic catalysts for hydrogenation

Abstract

The dependence of catalytic activity and selectivity of Cu-Ni bimetallic catalysts for oil hydrogenation on Cu∶Ni ratios have been investigated while they were reduced at low temperature (230 °C). Two maxima occurred at Cu₂Ni₁ and Cu₁Ni₃ in the activity-Cu∶Ni curve. Cu riched catalysts have higher selectivity than Ni riched ones, and may cause dehydrogenation and isomerization of linoleate at the beginning of the reaction. The structures of the catalysts reduced at different temperatures have been studied by means of XRD, XPS, EXAFS and FMR et al. The structure of the catalysts reduced at 230 °C can be described as an aggregate of Cu particles inlaid with Ni atoms and unreduced NiO, and the easily reduced Cu always segregates on the surface, while homogeneous solid solution particles can be formed in the case 400 °C being used as reduction temperature.