Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Tipo: Artigo em Revista Científica Internacional
• Data: 2019

Autores

José Luís Figueiredo (Autor) Outra; Manuel Fernando R. Pereira (Autor) FEUP; Rafael Morais (Autor) FEUP; Natalia Rey-Raap (Autor) Outra

Revista

Título: Beilstein Journal of Nanotechnology

Vol. 10

Páginas: 1089-1102

ISSN: 2190-4286

Editora: Beilstein-Institut Zur Forderung der Chemischen Wissenschaften

Indexação

ISI Web of Knowledge - 0 Citações

Scopus - 15 Citações

Projetos Associados

UnirCell - Project UniRCell - Unitised Regenerative Fuel Cell for Efficient Renewable Energy Supply: from Materials to Device

Outras Informações

ID Authenticus: P-00Q-MZ0

DOI: 10.3762/bjnano.10.109

Abstract (EN): Nitrogen-doped biomass-derived carbon materials were prepared by hydrothermal carbonization of glucose, and their textural and chemical properties were subsequently tailored to achieve materials with enhanced electrochemical performance towards the oxygen reduction reaction. Carbonization and physical activation were applied to modify the textural properties, while nitrogen functionalities were incorporated via different N-doping methodologies (ball milling and conventional methods) using melamine. A direct relationship between the microporosity of the activated carbons and the limiting current density was found, with the increase of microporosity leading to interesting improvements of the limiting current density. Regardless of the doping method used, similar amounts of nitrogen were incorporated into the carbon structures. However, significant differences were observed in the nitrogen functionalities according to the doping method applied: ball milling appeared to originate preferentially quaternary and oxidized nitrogen groups, while the formation of pyridinic and pyrrolic groups was favoured by conventional doping. The onset potential was improved and the two-electron mechanism of the original activated sample was shifted closer to a four-electron pathway due to the presence of nitrogen. Interestingly, the high pyridinic content related to a high ratio of pyridinic/quaternary nitrogen results in an increase of the onset potential, while a decrease in the quaternary/pyrrolic nitrogen ratio favors an increase in the number of electrons. Accordingly, the electrocatalyst with the highest performance was obtained from the activated sample doped with nitrogen by the conventional method, which combined the most appropriate textural and chemical properties: high microporosity and adequate proportion of the nitrogen functionalities.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14