Heterogenisation of a c-scorpionate feII complex on carbon materials for cyclohexane oxidation with hydrogen peroxide

• Autor(a) principal: Martins, Luisa
• Data de Publicação: 2013
• Outros Autores: Almeida, M. Peixoto de, Carabineiro, S. A. C., Figueiredo, J. L., Pombeiro, Armando
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/8648
• topic: Alkanes; Carbon; Iron; Heterogenization; Oxidation; Supported catalysts

The hydrotris(pyrazol-1-yl)methane iron(II) complex [FeCl2{h3-HC(pz)3}] (pz=pyrazol-1-yl) (1) was immobilized on three diferente carbon materials (activated carbon, carbon xerogel and multi-walled carbon nanotubes) with three different surface treatments (original, treated with nitric acid, and treated with nitric acid followed by sodium hydroxide) to produce active, selective and recyclable catalysts. The heterogenisation process was more efficient for carbon nanotubes treated with nitric acid and sodium hydroxide. An outstanding improved catalytic performance of complex 1 upon heterogenisation on carbon nanotubes treated with nitric acid and sodium hydroxide (turnover numbers up to 5.6_103 and overall yield of 21 %), relative to the homogeneous system, was achieved for the single-pot peroxidative oxidation of cyclohexane to the cyclohexanone and cyclohexanol mixture. The heterogenised systems allowed their easy recovery and reuse, at least for five consecutive cycles, maintaining 96% of the initial activity and concomitante rather high selectivity to cyclohexanol and cyclohexanone.