Nanoheterogeneous electrocatalysts fabricated by palladizing of platinum

Palladium samples deposited on platinum at constant potentials of 0.02-0.07 V (the reversible hydrogen electrode, the) are studied by measuring potent iodynamic and charging curves. These samples are shown to exhibit an anomal ous behavior throughout the whole region of reversibility, namely, the enha nced hydrogen contents in alpha- and beta-phases of palladium hydride and t he higher real surface areas. The parameters of the isotherms of the beta-p hase formation differ from those observed for usual palladium samples. The model analysis based on the defectiveness concept correlates the anomalousl y high hydrogen content and unusual isotherm parameters with the concentrat ion of defective lattice regions. (C) 2000 Elsevier Science Ltd. All rights reserved.