One-pot glycerol oxydehydration on multifunctional catalysts: influence of acid and redox properties on the catalytic performance
[EN] We report on a study of the key reaction parameters in glycerol oxidehydration into acrylic acid over W-V-Nb mixed oxides with a hexagonal tungsten bronze structure. This investigation demonstrated that the optimal control of the two consecutive steps of acid-catalysed glycerol dehydration into...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/134138 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/134138 |
| Access Level: | acceso abierto |
| Palabra clave: | Glycerol Acrylic acid Oxidehydration W-V-Nb mixed oxides Hexagonal tungsten bronze |
| Sumario: | [EN] We report on a study of the key reaction parameters in glycerol oxidehydration into acrylic acid over W-V-Nb mixed oxides with a hexagonal tungsten bronze structure. This investigation demonstrated that the optimal control of the two consecutive steps of acid-catalysed glycerol dehydration into acrolein and aldehyde oxidation into acrylic acid, and of the parallel reaction of acrolein transformation into by-products (ketals and oligomers), was achieved in the presence of a defined glycerol-to-oxygen inlet ratio. Indeed, oxygen played the fundamental role of accelerating the oxidation of the intermediately formed acrolein into acrylic acid, by allowing a greater concentration of the oxidizing V5+ sites. In fact, an unprecedented higher yield to acrylic acid and acrolein compared to W-V bronzes was registered (maximum acrylic acid yield 50.5%) together with an increase of more than one order of magnitude in productivity, because of both the greater concentration of glycerol used in the inlet feed and the lower contact time needed. Further experiments were carried out by reacting acrolein and methanol in oxidative conditions, the latter as a model molecule for the determination of surface acid and redox properties. |
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