PdAg films with self-supported porous dendritic walls were fabricated by hydrogen dynamic template method, which could provide as the transport channel due to the micron-sized pores and the interstices between the dendrites. Different composition PdAg catalysts were obtained by adjusting the proportion of Pd(NO₃)₂ and AgNO₃ and it was also studied that the effect of the addition of Ag on the catalytic performance for ethanol. The cyclic voltammetry (CV) curves showed that PdAg films possessed high catalytic activity for ethanol and the addition of Ag significantly increased the mass-normalized catalytic activity of Pd. The mass-normalized catalytic current density of porous Pd₅₁Ag₄₉ is 0.49 A/mg, and it was estimated as 1.47 times as porous Pd. X-ray photoelectron spectroscopy (XPS) study indicated that the enhancement of the catalytic activity of PdAg films could be ascribed to the change of the Pd electronic structure when Ag atoms are embedded into the Pd lattice to form PdAg alloy as shown in X-ray diffraction(XRD) and element analysis mapping (EM) results.