Effect of Fe-N-Cs as Catalytic Active Support for Platinum towards ORR in Acidic Environment

Kurzfassung

Metal-nitrogen-carbon (M-N-C) compounds such as Fe-N-Cs are currently the most promising platinum group metal free catalysts for oxygen reduction in acidic environment. Regarding the overriding goal of reducing PEMFC production costs by reducing the platinum content, the use of Fe-N-Cs as catalytic active support for low Pt amounts is investigated in this study. Activity and stability of Pt in different contents on a commercial Fe-N-C is compared to Pt on a typical carbon black. Pt nanoparticles are well-distributed on both support substrate classes. Although the electrochemical surface and mass activity of Pt is lower on Fe-N-C compared to carbon black, the Fe-N-C has a contribution to total ORR activity depending on the Pt/Fe-N-C ratio, which is quantified. In the low Pt content case of 1 wt, the ORR activity is increased by factor of two in presence of Fe-N-C. This boosting effect on ORR activity is important for future strategies to lower the Pt content in PEMFCs.