This paper deals with an investigation of hexagonal W–Nb–O and W–V–Nb–O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported that the best yield to acrylic acid obtained with the W–V–O bronze was 25%; in the current work, the incorporation of Nb in the tri-component bronze structure allowed us to obtain the best acrylic acid yield of 34%. The W–Nb–O bronze was an efficient acid catalyst for the dehydration of glycerol into acrolein – more selective than WO3 at temperatures lower than 300 ◦C –, whereas in the tri-component system the presence of V conferred to the catalyst the redox properties for the partial oxidation of acrolein into acrylic acid. The characterization of the catalysts confirmed the incorporation of Nb5+ in the hexagonal structure, and the generation of acid sites with enhanced strength compared to the bi-component W–V–O system. This also enhanced the stability of catalytic performance during short-term lifetime experiments.
Titolo: | Glycerol oxidehydration into acrolein and acrylic acid over W–V–Nb–O bronzes with hexagonal structure |
Autore/i: | CHIEREGATO, ALESSANDRO; BASILE, FRANCESCO; P. Concepción; GUIDETTI, STEFANIA; LIOSI, GIUSEPPE; M. D. Soriano; TREVISANUT, CRISTIAN; CAVANI, FABRIZIO; J. M. López Nieto |
Autore/i Unibo: | |
Anno: | 2012 |
Rivista: | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.cattod.2012.06.024 |
Abstract: | This paper deals with an investigation of hexagonal W–Nb–O and W–V–Nb–O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported that the best yield to acrylic acid obtained with the W–V–O bronze was 25%; in the current work, the incorporation of Nb in the tri-component bronze structure allowed us to obtain the best acrylic acid yield of 34%. The W–Nb–O bronze was an efficient acid catalyst for the dehydration of glycerol into acrolein – more selective than WO3 at temperatures lower than 300 ◦C –, whereas in the tri-component system the presence of V conferred to the catalyst the redox properties for the partial oxidation of acrolein into acrylic acid. The characterization of the catalysts confirmed the incorporation of Nb5+ in the hexagonal structure, and the generation of acid sites with enhanced strength compared to the bi-component W–V–O system. This also enhanced the stability of catalytic performance during short-term lifetime experiments. |
Data prodotto definitivo in UGOV: | 2013-06-16 16:10:30 |
Data stato definitivo: | 2015-12-05T18:17:03Z |
Appare nelle tipologie: | 1.01 Articolo in rivista |