Growing Tungsten Nanophases on Carbon Spheres Doped with Nitrogen. Behaviour as Electro-Catalysts for Oxygen Reduction Reaction Briz Amate, Teresa Castelo Quibén, Jesica Bailón García, Esther Carrasco Marín, Francisco Pérez Cadenas, Agustín Francisco Carbon nanospheres Tungsten carbide Carbon-tungsten composites Nitrogen-doped electro-catalysts Oxygen reduction reaction This research was funded by the Junta de Andalucia [grant numbers RNM172 and P18-RTJ-2974]. This work shows the preparation of carbon nanospheres with a high superficial nitrogen content (7 wt.%), obtained by a simple hydrothermal method, from pyrocatechol and formaldehyde, around which tungsten nanophases have been formed. One of these nanophases is tungsten carbide, whose electro-catalytic behavior in the ORR has been evaluated together with the presence of nitrogen surface groups. Both current and potential kinetic density values improve considerably with the presence of tungsten, despite the significant nitrogen loss detected during the carbonization treatment. However, the synergetic effect that the WC has with other electro-catalytic metals in this reaction cannot be easily evaluated with the nitrogen in these materials, since both contents vary in opposite ways. Nevertheless, all the prepared materials carried out oxygen electro-reduction by a mixed pathway of two and four electrons, showing remarkable electro-catalytic behavior. 2022-01-31T13:30:20Z 2022-01-31T13:30:20Z 2021-12-14 journal article Briz-Amate, T... [et al.]. Growing Tungsten Nanophases on Carbon Spheres Doped with Nitrogen. Behaviour as Electro-Catalysts for Oxygen Reduction Reaction. Materials 2021, 14, 7716. [https://doi.org/10.3390/ma14247716] http://hdl.handle.net/10481/72569 10.3390/ma14247716 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España MDPI