Adsorption of carbon monoxide on copper Infrared absorption spectra and thermodesorption

The chemisorption of carbon monoxide occurs in two states with about 10 kcal/mole and 20 kcal/mole heat of adsorption and with low activation energies for adsorption. The infrared absorption spectra and thermodesorption characteristics for both these states are complex. In addition, thermodesorption indicates the presence of a state with a higher activation energy for desorption than these. The infrared spectra of physically adsorbed carbon monoxide and carbon monoxide chemisorbed on silica are also given. The frequency of the carbon monoxide spectra is related to the type of bonding with the surface.