Infrared study of CO adsorption on Pd particles supported on NaCl(1 0 0)

The adsorption of CO on Pd particles epitaxially grown on NaCl(1 0 0) has been studied by IR absorption spectroscopy in transmission mode. In comparison with Pd particles grown on MgO(1 0 0) the IR spectra show a large extension of the absorption band down to 1550 cm−1. Otherwise the high frequency band is similar and can be interpreted in term of adsorption on crystalline facets. Several explanations are discussed to understand the presence of very low CO stretching frequencies. The most reasonable one is the presence of sodium on the Pd particles coming from the NaCl support.