Cobalt and Nitrogen Co-Doped Peat Derived Carbon Based Catalysts for Oxygen Reduction

Abstract

The carbon precursor peat is one out of many mineral-rich resources of Estonia, which originally is a sediment of incompletely decomposed plant residues. The chemical properties of peat include the five basic elements: C, H, O, N and S [1]. Therefore, its composition is attractive and economically perspective not only for the synthesis of nonprecious catalysts for the oxygen reduction reaction (ORR), but also as a framework for batteries [2]. Generally, nonprecious metal and nitrogen co-doped catalysts have been synthesized using a metal salt, a nitrogen precursor and a carbon material via either one or multiple step preparation methods [3,4]. Herein, we introduce promising peat derived carbon (PDC) based cobalt and nitrogen co-doped catalysts (Co-N/PDCX) which demonstrate high catalytic activity towards ORR. The nanoporous carbon support was derived from peat via five different carbonization protocols (see Scheme). All the prepared PDCX and Co-N/PDCX catalysts were characterized by several physical characterization methods. The ORR activity of the synthesized PDCX and Co-N/PDCX catalysts were investigated in 0.1 M HClO4 solutions using rotating disc electrode method and the ORR activity of Co-N/PDCX shows significant dependence on the carbonization method used to derive a carbon support. The best catalyst was chosen for further testing in a fuel cell. Acknowledgements This work was supported by the EU through the European Regional Development Fund under project TK141 “Advanced materials and high-technology devices for energy recuperation systems” (2014-2020.4.01.15-0011), by the Estonian institutional research grant No. IUT20-13, NAMUR ”Nanomaterials - research and applications” (3.2.0304.12-0397) and LLTOM17351 “Activated carbon from peat” (01.07.2017-30.06.2020).