Nitrogen-doped Carbon Nanomaterials As Highly Efficient Catalysts For Oxygen Reduction Reaction

Oxygen reduction reaction?ORR?is of great importance for new energy conversion technologies such as fuel cells and metal-air batteries.Nitrogen-doped carbon materials have proven to be robust electrocatalysts for ORR in above-mentioned new energy devices.In this dissertation,iron and nitrogen co-doped carbon materials?Fe-N/AC and Fe₃O₄/N-AC?as efficient non-noble-metal catalysts for ORR were synthesized by the pyrolysis procedure.And we fabricated a novel nitrogen-doped porous carbon nanoplatelets?N-PCNPs?as one efficient non-metal catalyst for ORR by a two-step method.These hybrids were analyzed by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray diffraction?XRD?,X-ray photoelectron spectroscopy?XPS?and Raman spectroscopy.The ORR properties of these composites were also tested by electrochemical methods including cyclic voltammetry?CV?,rotating disk electrode?RDE?,rotating ring-disk electrode?RRDE?and chronoamperometry techniques.The results showed that the proposed Fe-N/AC hybrid had good catalytic performance toward ORR in alkaline media;Fe₃O₄/N-AC and N-PCNPs exhibited excellent performance towards ORR in both acid and alkaline media.Furthermore,all of the as-prepared catalysts followed four-electron ORR mechanism and possessed better methanol tolerance and excellent operational durability.As a result,our proposed catalysts hold great potential as low-cost,highly-efficient cathode materials in direct methanol fuel cells?DMFCs?.