Platinum nanoparticles are an excellent catalyst for oxidation/evolution of hydrogen, oxygen reduction reaction and oxidation of small organic molecules fuels such as ethanol, methanol, and formic acid. In recent years, solutions-based techniques have attracted great interest due to their advantage in controlling reaction parameters. Among the techniques, amine-based seed-mediated solvothermal growth provides a versatile method for the production of various Pt nanoparticles. However, the amine species that functioned as the stabilizing agent would absorb at the surface of Pt, resulting in poor electrocatalytic performance. For this reason, the amine ligand must be removed in order to reveal the expected catalytic performance of Pt. In this work, we proposed a combination strategy that employed acid treatment under gentle heating followed by thermal treatment to remove the amine ligand and investigate their catalytic effect on formic acid oxidation. The acid wash involved in subjecting the catalyst in acetic acid glacial at 85 degrees C for 1 h + 9 h of heat treatment at 85 degrees C in air atmosphere. The experimental procedures were repeated by subjecting the Pt to 3 h in acetic acid + 7 h of heat treatment, followed by 5 h in acetic acid + 5 h heat treatment and a single treatment by immersing the Pt nanoparticles in acetic acid for 10 h. We reported that this combined activation technique improves significantly the performance of Pt nanoparticles in catalyzing formic acid oxidation. The results showed that 3 h of acid wash + 7 h of thermal treatment is the optimal condition for a high electrochemical surface area (ECSA) value of 1.006 +/- 0.02 m(2)/g, lower coverage of CO adsorption and a steady-state current of 3.03 mA/cm(2) made at 0.67 V (vs. SCE) at 1000 s during formic acid oxidation. This approach could become a potential procedure for activating the Pt surface attached by amine ligand. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.