Combita Merchán, DF.; Concepción Heydorn, P.; Corma Canós, A. (2014). Gold catalysts for the synthesis of aromatic azocompounds from nitroaromatics in one step. Journal of Catalysis. 311:339-349. doi:10.1016/j.jcat.2013.12.014
Por favor, use este identificador para citar o enlazar este ítem: http://hdl.handle.net/10251/62368
Title:
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Gold catalysts for the synthesis of aromatic azocompounds from nitroaromatics in one step
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Author:
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Cómbita Merchán, Diego Fernando
Concepción Heydorn, Patricia
Corma Canós, Avelino
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UPV Unit:
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Universitat Politècnica de València. Instituto Universitario Mixto de Tecnología Química - Institut Universitari Mixt de Tecnologia Química
Universitat Politècnica de València. Departamento de Química - Departament de Química
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Issued date:
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Abstract:
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[EN] One-step selective hydrogenation of nitroaromatics to obtain symmetric azocompounds with high yields
has been performed with a gold supported on cerium oxide catalysts. Au/TiO2 and Au/CeO2 catalysts
direct the ...[+]
[EN] One-step selective hydrogenation of nitroaromatics to obtain symmetric azocompounds with high yields
has been performed with a gold supported on cerium oxide catalysts. Au/TiO2 and Au/CeO2 catalysts
direct the reaction by two different pathways and with different selectivities. In situ FTIR studies reveal
that the surface concentration of the intermediate nitrosobenzene is decisive in directing the reaction
trough the different reaction pathways. In this way, while on Au/TiO2 a fast hydrogenation of the
nitrosobenzene intermediate leads to a low surface concentration of the nitrosocompound, on Au/CeO2
nitrosobenzene is more stabilized on the catalyst surface leading to a lower hydrogenation and a higher
coupling rate, resulting in high selectivities to azobenzene. On Au/CeO2, the relative weak adsorption of
the azo with respect to the azoxycompound on the catalyst surface avoids the consecutive hydrogenation
of azocompounds to the corresponding anilines until all the azoxy has been consumed. Asymmetric
azobenzenes have also been obtained with very high yields on TiO2, through the Mills reaction.
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Subjects:
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Azocompounds
,
Nitroaromatics reduction
,
Heterogeneous catalysts
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Gold catalysts
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Hydrogenation
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Copyrigths:
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Reserva de todos los derechos
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Source:
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Journal of Catalysis. (issn:
0021-9517
) (eissn:
1090-2694
)
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DOI:
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10.1016/j.jcat.2013.12.014
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Publisher:
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Elsevier
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Publisher version:
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http://dx.doi.org/10.1016/j.jcat.2013.12.014
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Project ID:
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MINECO/CSD2009-00050
MICINN/SEV-2012-0267
MEC/MAT2006-14274-C02-01
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Thanks:
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The authors wish to acknowledge the financial support from the Spanish Ministries of Education and Science and Economy and Competitiveness under the project Consolider-Ingenio 2010 (CSD2009-00050 "Development of more ...[+]
The authors wish to acknowledge the financial support from the Spanish Ministries of Education and Science and Economy and Competitiveness under the project Consolider-Ingenio 2010 (CSD2009-00050 "Development of more efficient catalysts for the design of sustainable chemical processes and clean energy production") and the Severo Ochoa program (SEV-2012-0267), respectively. D.C. thanks the Spanish MEC for postgraduate scholarship, project MAT2006-14274-C02-01.
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Type:
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Artículo
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