Role of Nitrogen Doping on the Performance of Carbon Nanotube Catalysts: A Catalytic Wet Peroxide Oxidation Application

• Tipo: Artigo em Revista Científica Internacional
• Data: 2016

Autores

Maria Martin-Martinez (Autor) Outra; Rui S. Ribeiro (Autor) FEUP; Bruno F. Machado (Autor) FEUP; Philippe Serp (Autor) Outra; Sergio Morales Torres (Autor) FEUP; Adrián M. T. Silva (Autor) FEUP; José L. Figueiredo (Autor) FEUP; Joaquim L. Faria (Autor) FEUP; Helder T. Gomes (Autor) FEUP

Revista

Título: ChemCatChem

Vol. 8 Nº 12

Páginas: 2068-2078

ISSN: 1867-3880

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 7 Citações

Scopus - 24 Citações

Projetos Associados

LSRE-LCM - Laboratório de Processos de Separação e Reação - Laboratório de Catálise e Materiais

Outras Informações

ID Authenticus: P-00K-KVD

DOI: 10.1002/cctc.201600123

Abstract (EN): Four magnetic carbon nanotube (CNT) samples (undoped, completely N-doped, and two selectively N-doped) were synthesized by chemical vapor deposition. The materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated 4-nitrophenol solutions (4-NP, 5gL(-1)). Relatively mild operating conditions were considered (atmospheric pressure, T=50 degrees C, pH3), using a catalyst load of 2.5gL(-1) and the stoichiometric amount of H2O2 needed for the complete mineralization of 4-NP. N-doping was identified to influence considerably the CWPO performance of the materials. In particular, undoped CNTs, with a moderate hydrophobicity, favor the controllable and efficient decomposition of H2O2 into highly reactive hydroxyl radicals (HO.), thus showing high catalytic activity for 4-NP degradation. On the other hand, the completely N-doped catalyst, fully hydrophilic, favors a quick decomposition of H2O2 into nonreactive O-2 and H2O species. The selectively N-doped amphiphilic catalysts, that is, hybrid structures containing undoped sections followed by N-doped ones, provided intermediate results, namely, a higher N content favored H2O2 decomposition towards nonreactive H2O and O-2 species, whereas a lower N content resulted in the formation of HO., increasing 4-NP mineralization. Catalyst stability and reusability were also investigated by consecutive CWPO runs.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11