Catalytically active highly metallic palladium (A-I-Pd/C) catalyst for oxidation of formate (HCOO-) was synthesized via borohydride reduction method assisted by ammonia and iodine ion. The physico-chemical characterizations were conducted to investigate properties of the synthesized catalysts and we confirmed A-I-Pd/C is consisted with palladium hydride. The catalytic activity of the catalysts for oxidation of HCOO- are characterized by electrochemical analysis and A-I-Pd/C catalysts performed the best catalytic activity for oxidation of HCOO- in terms of Tafel slope and onset potential. The enhanced catalytic activity of A-I-Pd/C is explained by enhanced kinetics of oxidation of H-ads, which is caused by weaken adsorption strength of H-ads on Pd due to electron transfer from H to Pd. The enhanced performance of A-I-Pd/C was also confirmed and compared with the others in a single cell system.