Infrared-Band Intensities of Adsorbed Carbon Monoxide

Abstract

It has been possible in favorable cases to measure the intensities of the infrared bands of CO adsorbed on different ZnO and supported Cu, CuO, and Pt catalyst surfaces. For weak, reversible adsorption at room temperature, giving rise to the bands in the frequency region 2132–2212 cm−1, a unique correlation between intensity and frequency was found which apparently holds for a number of chemically different substrates. Values for both gaseous and dissolved CO fit the correlation reasonably well. A tentative explanation in terms of small perturbations of the dipole moment of CO(g) was advanced. Measurements in the metal carbonyl region were complicated by the formation of multiple-surface species and volatile products [Ni(CO)4].