Calorimetric study of the adsorption of carbon monoxide, at 296 K, on supported nickel and nickel–copper catalysts

Abstract

A calorimetric study of the adsorption of carbon monoxide, at 296 K, on a series of silica-supported nickel and nickel–copper catalysts was carried out. The experimental results were compared with previously published i.r. spectroscopic and magnetic data for the same systems. In agreement with the Chatt–Dewar model for CO chemisorption on metals, changes of the heat of formation of metal–CO bonds can always be associated with shifts of the frequency of the C—O stretching vibration. The heat of the metal–CO bond formation appears to be related to the position of the Fermi level at the metal surface. Formation of both linear and bridged adspecies, in definite proportions on each alloy, would obey a concerted mechanism, controlled by the electronic properties of the surface nickel atoms.