Nitrogen and Phosphorus Dual-Doped Silicon Carbide-Derived Carbon/Carbon Nanotube Composite for the Anion-Exchange Membrane Fuel Cell Cathode

• Published in: ACS applied energy materials 2022-03, Vol.5 (3), p.2949-2958
• Main Authors: Palm, Iris, Kibena-Põldsepp, Elo, Mooste, Marek, Kozlova, Jekaterina, Käärik, Maike, Kikas, Arvo, Treshchalov, Alexey, Leis, Jaan, Kisand, Vambola, Tamm, Aile, Holdcroft, Steven, Atanassov, Plamen, Tammeveski, Kaido
• Format: Article
• Language: English
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.1c03627

Dual heteroatom (N,P)-doped catalysts based on the composite of silicon carbide-derived carbon (SiCDC) and carbon nanotubes (CNTs) or solely CNTs were prepared for oxygen reduction reaction (ORR) using melamine phosphate as nitrogen and phosphorus precursors. The half-cell test conducted by the rotating ring-disk electrode method exhibited a high ORR electrocatalytic activity for N,P-SiCDC/CNT with an onset potential of 0.91 V and a half-wave potential of 0.80 V in alkaline solution. Similar ORR results were obtained with N,P-CNT. The dual heteroatom-doped SiCDC/CNT composite as a cathode catalyst exhibited an impressive peak power density of 538 mW cm–2 in an anion-exchange membrane fuel cell (AEMFC) test. The superior AEMFC performance of this catalyst could be attributed to (i) the high specific surface area along with hierarchical porosity (micro/mesopores) as revealed by the N2 physisorption analysis, (ii) high defect density (I D/I G = 1.54) determined by Raman spectroscopy analysis, and (iii) successful doping of N and P moieties into the carbon materials as revealed by X-ray photoelectron spectroscopy and scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy.