Platinum-based catalysts are a key to develop direct methanol fuel cells, which are usually dispersed on carbon supports to enhance catalytic activity, stability and utilization. Here, platinum/nitrogen-doped carbon (Pt/N-C) nanoparticles are synthesized in nitrogen-doped carbon quantum dots (N-CQDs) aqueous solution, and catalytic performance of Pt/N-C catalysts is researched for methanol electro-oxidation. Compared with Pt catalysts supported on commercial carbon black Vulcan XC-72 (Pt/XC-72), the peak current densities of Pt/N-C catalysts are 0.59 mA cm(-2) Pt and 385.2 A g(-1) Pt in 0.5 M CH3OH and 0.5 M H2SO4, while those of Pt/XC-72 catalysts are 0.39 mA cm(-2) Pt and 64.8 A g(-1) Pt. After polarizing 7200 s at a fixed potential of 0.15 V (vs. Hg/Hg2SO4), the catalytic activities of Pt/N-C are 0.14 mA cm(-2) Pt and 86.5 A g(-1) Pt, and those of Pt/XC-72 are 0.02 mA cm(-2) Pt and 2.6 A g(-1) Pt. (C) 2016 Elsevier Ltd. All rights reserved.