Role of the Support in Determining the Vibrational Properties of Carbonyls Formed on Pd Supported on SiO2-Al2O3, Al2O3, and MgO

The vibrational properties of adsorbed carbonyls on heterogeneous Pd/oxide systems (SiO2-Al2O3, Al2O3, and MgO) are compared and discussed. On the basis of the surface science literature, the complex IR spectra of carbonyls formed on Pd particles are interpreted in terms of what occurs on well-defined Pd(111) and Pd(100) faces and on edge/corner defects, typical of metal nanoparticles, thus bridging the gap between single crystals and high surface area systems. Furthermore, the influence of the electronic properties of the support (i.e., surface acidity/basicity) in determining the spectral features of carbonyls formed on Pd particles is clearly demonstrated.