Cerium-palladium surface alloys have been studied by x-ray and ultraviolet photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and photoemission electron microscopy. Desorption of CO has been studied by temperature programed desorption spectroscopy. Thin layers of Cc were deposited on Pd(111) and Pd(110) single crystal substrates to form surface alloys upon annealing to 1000 K. An enrichment of Pd at the surface is observed and the work functions of the surface alloys are found to be 0.2-0.6 eV less than the value for the bare Pd substrate, which are substantially larger than the values for the as-deposited Ce-Pd samples. Several different LEED patterns were observed depending on the annealing temperature. The estimated Cc valence from XPS was found to be in the range from 3.16 to 3.22 for the surface alloys after annealing. (c) 2007 American Vacuum Society.