Chemisorption on Copper

Although it is much less active than the transition metals copper does catalyse reactions of hydrogen and carbon monoxide. The nature of the weak adsorptions of these gases has been investigated by surface potentials, low energy electron diffraction, and infrared spectroscopy. Hydrogen is dissociatively adsorbed by copper but the adsorption is activated. Surface potential measurements have provided isotherms and isosteric heats of adsorption. Carbon monoxide is adsorbed in two distinct stages giving positive and negative surface potential changes. The positive stage is accompanied by a sharp infrared absorption band near 2100 cm−1 which is sufficiently strong to permit reflection spectroscopic studies on single crystal surfaces. Frequency shifts occur during the negative stage. Direct comparisons of surface potentials, diffraction patterns, and vibrational frequencies have been made and will be discussed in relation to the chemisorption bond.