Surface and redox properties of cobalt-ceria binary oxides: on the effect of Co content and pretreatment conditions

• Tipo: Artigo em Revista Científica Internacional
• Data: 2015

Autores

Michalis Konsolakis (Autor) Outra; Michalis Sgourakis (Autor) Outra; Sónia A. C. Carabineiro (Autor) FEUP

Revista

Título: Applied Surface Science

Vol. 341

Páginas: 48-54

ISSN: 0169-4332

Editora: Elsevier

Indexação

ISI Web of Knowledge

Scopus

INSPEC

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

CORDIS: Ciências Físicas > Química ; Ciências Tecnológicas > Engenharia > Engenharia química

Projetos Associados

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

Outras Informações

DOI: 10.1016/j.apsusc.2015.02.188

Abstract (EN): tCeria-based transition metal catalysts have recently received considerable attention both in heteroge-neous catalysis and electro-catalysis fields, due to their unique physicochemical characteristics. Theircatalytic performance is greatly affected by the surface local chemistry and oxygen vacancies. The presentstudy aims at investigating the impact of Co/Ce ratio and pretreatment conditions on the surface andredox properties of cobalt–ceria binary oxides. Co–ceria mixed oxides with different Co content (0, 20,30, 60, 100 wt.%) were prepared by impregnation method and characterized by means of N2adsorption at−196◦C, X-ray diffraction (XRD), H2temperature-programmed reduction (H2-TPR) and X-ray photoelec-tron spectroscopy (XPS). The results shown the improved reducibility of Co/CeO2mixed oxides comparedto single oxides, due to a synergistic interaction between cobalt and cerium. Oxidation pretreatmentresults in a preferential localization of cerium species on the outer surface. In contrast, a uniform distri-bution of cobalt and cerium species over the entire catalyst surface is obtained by the reduction process,which facilitates the formation of oxygen vacancies though Co3+/Co2+and Ce3+/Ce4+redox cycles. Funda-mental insights toward tuning the surface chemistry of cobalt–ceria binary oxides are provided, pavingthe way for real-life industrial applications.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7