Inexpensive Ipomoea aquatica biomass-modified carbon black as an active Pt-free electrocatalyst for oxygen reduction reaction in an alkaline medium

Abstract

The development of inexpensive and active Pt-free catalysts as an alternative to Pt-based catalysts for oxygen reduction reaction (ORR) is an essential prerequisite for fuel cell commercialization. In this paper, we report a strategy for the design of a new Fe-N/C electrocatalyst derived from the co-pyrolysis of Ipomoea aquatica biomass, carbon black (Vulcan XC-72R) and FeCl3. 6H2O at 900 °C under nitrogen atmosphere. Electrochemical results show that the Fe-N/C catalyst exhibits higher electrocatalytic activity for ORR, longer durability and higher tolerance to methanol compared to a commercial Pt/C catalyst (40 wt %) in an alkaline medium. In particular, Fe-N/C presents an onset potential of 0.05 V (vs. Hg/HgO) for ORR in an alkaline medium, with an electron transfer number (n) of ~3.90, which is close to that of Pt/C. Our results confirm that the catalyst derived from I. aquatica and carbon black is a promising non-noble metal catalyst as an alternative to commercial Pt/C catalysts.