Particle Size Effects in Pd-Catalyzed Electrooxidation of Formic Acid

Small carbon-supported Pd nanoparticles with controllable size (2.7−9.0 nm) were prepared by a solution chemistry method, characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopies, and evaluated as anode catalysts for the electrooxidation of formic acid at room temperature. Measurements of catalytic activity by electrochemical methods (cyclic voltammetry and chronoamperometry) revealed a strong potential-dependent particle size effect. Classical volcano plots of catalytic activity vs particle size were obtained from which the optimal Pd particle size for the respective potential region was determined.