A novel and efficient nitrogen-doped carbon nanotube (A-M-CNT) catalyst has been prepared by a facile two-step method, including prior air activation and subsequent pyrolysis of the carbon nanotubes with melamine. The as-synthesized A-M-CNT affords superior catalytic activity to the nitrogen-doped CNT without air activation (M-CNT) and pristine CNT, ascribed to its unique microstructure and surface chemical properties.