Abstract
This paper focuses on the morphological nature of Pd electrodeposited on different carbon supports such as Vulcan XC-72R (VCX), carbon nanotubes (CNTs) and wood apple shell carbon (WASC), and presents a comparative assessment of the catalytic activity on different supports towards formic acid (HCOOH) oxidation and oxygen reduction reaction (ORR) in low-temperature fuel cells. The carbon supports subjected to an electrochemical activation by potential cycling in an acidic media followed by deposition of Pd showed dendrite formation as confirmed by scanning electron micrographs irrespective of the morphology of carbon material. Pd dendrites on WASC showed the highest electrochemical surface area of 86.1 m2g-1 among the electrocatalysts studied. The carbon supported Pd dendrite showed the following order towards the activity of formic acid oxidation: WASC > VXC > CNTs, whereas for oxygen reduction reaction the activity was in the order CNTs > WASC > VXC. The results suggest the need for different carbon support for anode and cathode reaction of direct liquid fuel cells.