Electrodeposition of dendritic palladium nanostructures on carbon support for direct formic acid fuel cells

Palladium (Pd) dendrites were synthesized on electrochemically activated carbon (Vulcan XC-72R) support by a simple template free potentiostatic (constant voltage) deposition. Scanning electron micrographs displayed a dendritic morphology when deposited at potentials <0.5 V (vs. RHE), whereas spherical aggregates were obtained at potentials >0.5 V. Transmission electron micrographs and X-ray diffraction pattern confirmed the difference in morphological features and growth of Pd dendrites. Pd deposited at 0.4 V showed higher electrochemical surface area of 128.5 m(2) g(-1) in comparison to 25.1 m(2) g(-1) obtained for Pd deposited at 0.5 V and also displayed enhanced activity towards formic acid oxidation. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.