Transmission electron microscopy (TEM) and temperature programmed desorption (TPD) have been used in a complimentary manner to characterize particulate palladium films prepared on ‘‘hydroxylated’’ and ‘‘dehydroxylated’’ mica. The state of dehydroxylation was assessed by electron energy loss spectroscopy. In both cases TEM shows almost perfect epitaxial growth of Pd with the Pd{111} parallel to the mica surface. Particle number density is increased and mean particle diameter decreased on dehydroxylated mica. TPD of CO indicates mainly Pd{100} and Pd{111} facets on hydroxylated and dehydroxylated mica, respectively. On hydroxylated mica, additional CO binding states are found on thicker deposits having energies characteristic of more open crystal faces.