Effect of structural differences of carbon nanotubes and graphene based iridium-NHC materials on the hydrogen transfer catalytic activity

Blanco, M. ; Álvarez, P. ; Blanco, C. ; Jiménez, M. V. (Universidad de Zaragoza) ; Fernández-Tornos, J. ; Pérez-Torrente, J. J. (Universidad de Zaragoza) ; Blasco, J. (Universidad de Zaragoza) ; Subías, G. (Universidad de Zaragoza) ; Cuartero, V. ; Oro, L. A. (Universidad de Zaragoza) ; Menéndez, R.

Resumen: A proper design of heterogeneous molecular catalysts supported on carbon materials requires a systematic study of "metal-carbon support interactions" and their influence on catalytic activity. In this study, hybrid materials containing covalently anchored iridium N-heterocyclic carbene (NHC) organometallic complexes have been successfully prepared from oxidized and partially reduced carbon nanotubes (CNTs). The preparation method for these supported materials relies on the selective functionalization of the superficial hydroxylic groups using the imidazolium salt, 1-(3-hydroxypropyl)-3-methyl-1H-imidazol-3-ium chloride. The hydrogen transfer catalysis activity of these nanotube-based hybrid catalysts was tested by the reduction of cyclohexanone to cyclohexanol with 2-propanol, and the results of the tests were compared with those obtained using similar hybrid graphene-based catalysts. While EXAFS analysis revealed a common first coordination shell of the iridium atom for all the hybrid materials examined, independently of whether they were either supported on carbon nanotubes or graphene materials, catalytic activity in all the reduced materials was significantly superior. Moreover, catalytic systems based on reduced CNTs exhibited a better performance than those based on reduced graphene materials. Both these facts suggest there is a positive correlation between hydrogen transfer catalytic activity, reconstruction of the aromatic carbon structure and the smaller amount of oxygen functional groups.

Idioma: Inglés

DOI: 10.1016/j.carbon.2015.09.018

Año: 2016

Publicado en: Carbon 96 (2016), 66-74
ISSN: 0008-6223

Factor impacto JCR: 6.337 (2016)

Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 32 / 273 = 0.117 (2016) - Q1 - T1
Categ. JCR: CHEMISTRY, PHYSICAL rank: 23 / 144 = 0.16 (2016) - Q1 - T1

Factor impacto SCIMAGO: 2.091 - Chemistry (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MEC/AP2010-0025
Financiación: info:eu-repo/grantAgreement/ES/MINECO/AP2010-0025
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CSD2009-00050
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2013-42532-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/CTQ2013-42532-P

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Química Inorgánica (Dpto. Química Inorgánica)
Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)