Carbon quantum dots (CQDs) are synthesized by one pot electrochemical method using small molecule and applied as the support materials for platinum (Pt) catalysts. The effect of CQD on the catalytic activity and stability of the supported Pt catalysts for oxygen reduction reaction is investigated for the first time. The as-prepared Pt/CQD nano composites has been carefully characterized by spectroscopic and electrochemical techniques. X-ray diffractometer and tunneling electron microscopy techniques are employed to study the crystallite size. X-ray photoelectron spectroscopy revealed that Pt deposited to CQD. The electrochemical behavior, characterized by oxygen reduction reaction onset potentials, electrochemical active surface area, cyclic voltammetry stability (1000 cycles) and charge transfer resistance is attributed to the strong interaction between the nanosize platinum particles and the CQDs composite, which induces modulation in the electronic structure of the platinum clusters. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.