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Pd films of about 4.5 ± 0.5 nm were deposited on different transition metals (M = Co, Cu, Ag, and Au) by vapor deposition, and characterized by X-ray photoelectron spectroscopy (XPS), cyclic voltammetric (CV), and chronoamperometric (CA) tests. The Tafel method was used to determine the rate constant parameters, k⁰. The d-band center of the Pd–M samples exhibits a shift away from the Fermi level in the increasing order of Pd–Co, –Cu, –Ag, and –Au films compared to that of the bulk Pd film. As the position of the d-band center downshifts to a critical value, a weaker bond between Pd and formate (HCOO) is expected for the formic acid oxidation resulting in an improved electrochemical activity of the Pd surface for the Pd–Co and –Cu bimetallic films. As a critical value of the d-band center is reached formate is more difficult to adsorb on the Pd surface and its electrochemical activity toward formic acid oxidation …