Porous carbon spheres (PCSs) are prepared via a facile hydrothermal carbonization and chemical activation route with pectin as the biomass precursor. The as-obtained PCSs present a large specific surface area (2440m2 g−1), well-balanced micro/mesoporosity with narrow pore size distribution and high content of oxygen-containing functional groups. The structure features make the PCSs an ideal electrode material for electrochemical energy storage. As electrode material for supercapacitors, the PCSs exhibit a high specific capacitance, good rate capacity and cycling stability. Furthermore, the PCSs show attractive property as support material for Pt electrocatalysts. Pt nanowires (PtNWs) grown on the PCSs interconnect with each other to form a porous nanowires network structure. The three-dimensional (3D) hybrid catalyst material consisting of PtNWs network supported on PCSs exhibit superior catalytic activity and stability towards both methanol and ethanol electro-oxidation in acidic media. In addition, owing to the rich presence of surface oxygen groups on PCSs, the CO-poisoning tolerance of the supported Pt nanowires is greatly promoted.