Effect of Nitrogen-Doped Carbon Support on the Performance of Catalysts for the Oxygen Reduction Reaction

The development of efficient and stable catalysts is the key to promoting the in-depth application of proton exchange membrane fuel cells. Nitrogen-doped modification of the carbon support can effectively improve the dispersion of Pt nanoparticles and further improve the performance and durability of the catalyst. By simply adjusting the annealing temperature, the regulation of the nitrogen content was realized without changing the pore size distribution of the carbon supports. It was found that the amount of nitrogen doping is positively correlated with the dispersion of Pt. The average particle size of platinum nanoparticles decreased to 1.7-2.5 nm, indicating a better dispersion of Pt. The nitrogen-doped Pt/C catalysts have similar SA, which proved that the nitrogen-containing sites have a limited effect on the intrinsic activity of the catalyst. It indicated that the nitrogen active site on the carbon support was not the main contribution to the activity, while its effect on catalyst particle size and dispersion was the key factor. The catalysts supported by CB-N-800 had the best performance (284 mA/mgPt, 16% degradation after 30k cycles). It also showed good performance in membrane electrode assembly. The maximum power density of MEA-N-800 was 0.91 W/cm(2), and the decay rate was just 6.9%. It provides a promising approach to designing high-performance catalysts for practical application.