Iron-nitrogen-doped mesoporous tungsten carbide nanostructures as oxygen reduction electrocatalystsElectronic supplementary information (ESI) available: Additional figures. See DOI: 10.1039/c4cp01157k

Since Pt-based catalysts have the disadvantages of high cost, large overpotential loss, and limited long-term stability, there have been various promising alternatives to Pt-based catalysts to improve the catalytic activity towards the oxygen reduction reaction (ORR). We have synthesized iron-nitrogen-doped mesoporous tungsten carbide catalysts (WC-m-FT) by pyrolysis of well-ordered mesoporous tungsten carbides with iron porphyrin. WC-m-FT exhibits excellent ORR catalytic activity in an alkaline medium, i.e. a high electron-transfer number as well as superior stability and methanol tolerance. The improved activity and stability of WC-m-FT are ascribed to iron-containing catalytic active sites surrounded by nitrogen species and the well-defined mesoporous tungsten carbide structure. WC-m-FT shows excellent electrochemical properties towards the oxygen reduction reaction (ORR) due to the iron and nitrogen species acting as catalytic sites and the mesoporous structure.