Platinum (Pt) nanocrystals of cubic and octopod structures were synthesized via seed-mediated solvothermal growth with monoethanolamine as the solvent. The combination of nanocube and octopod structures was formed using 0.025 ml seeds loading, while increasing the seeds volume to 0.050 ml and 0.100 ml produced nanocube as the primary product. The octopod structure evolves from the overgrown nanocube via kinetic growth mechanism. Pt nanocube formed with 0.050 ml seeded solution has the potential to serve as a catalyst in formic acid oxidation by virtue of its high electrochemical surface area of 10.93 m(2)/g, over that of Pt black at 8.62 m(2)/g and resistance to poisonous CO. Nonetheless, it is less catalytically active in ethanol oxidation as depicted by the small electrochemical surface area of 8.64 m(2)/g and low current density in longer period. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.