N-doped cnt as a metal-free catalyst for reduction of nitro-benzene derivatives

Trabajo presentado en el 9º Encontro Nacional de Catálise e Materiais Porosos, celebrado en Oporto (Portugal) del 6 al 7 de mayo de 2013.Nitroaromatic compounds are commonly used in many industrial processes, including the preparation of pesticides, explosives, textiles and paper. Therefore, they are often detected as water pollutants as a result of their release in industrial effluents. Wastewaters remediation containing these pollutants is very problematic, since they are usually resistant to conventional degradation treatrnents. The physical- and chemical properties of carbon nanotubes (CNTs), particularly the basic character, can be tailored by the incorporation of nitrogen atoms in their structure. [2] N-doped CNTs have been proposed as supports for metal catalysts. Besides, these materials have been also used as metal-free catalysts for the selective oxidation of H2 S reaction, the oxygen reduction reaction or base-catalysed reactions.Here, we report the first use of CNT-N as a metal-free catalyst for the reduction of 4-nitrophenol (4NP) and 4-nitroaniline (4NA) in the presence of NaBH4 . Carbon nanotubes (CNT-N) were synthesized in a fluidized-bed reactor, over a Fe/Si02 catalyst, by catalytic chemical vapour decomposition of acetonitrile vapour and were characterized by transmission electron microscopy (TEM), N2 adsorption isotherm determination (BET) and X-ray photoelectron spectroscopy (XPS). The catalytic experiments were monitored by UV-Vis and the products of the reactions were characterized by 1HNMR.Support for this work was provided by FCT and FEDER through grant PEst­ C/EQB/LA0006/20l1, A95es Integradas Luso-Espanholas E 20/l l and Acciones Integradas AIB20lOPT-00104. MR, BJ and MA thank FCT for their grants.Peer Reviewe