This work deals with preparation and characterization of H3PW12O40 (H3PW) supported on silica-alumina. Impregnation of H3PW (15, 20, 30 and 40 wt.%) on commercial silica-alumina support in acidic aqueous solution is effective for preparing this catalyst keeping its Keggin structure, according to different methods of characterization. The catalysts were tested in a model reaction of acetic acid with ethanol and 30 wt.% H3PW/SiO2-Al2O3 had the highest activity under the conditions: catalyst calcination at 300°C, temperature of 100°C, acetic acid:ethanol molar ratio of 2:1 and catalyst:acetic acid mass ratio of 10 wt.%. The reaction yield was 79 and 100% selectivity for ethyl acetate over three reutilizations, for reaction time of 2 h. The calculated total acid site distribution was 0.299 mmol g-1 (97% of the theoretical probed by pyridine), and most of these (0.236 mmol g-1) were Brønsted weak-medium strength (pyridine desorption between 300 and 500°C).
CITATION STYLE
De Mattos, F. C. G., De Carvalho, E. N. C. B., De Freitas, E. F., Paiva, M. F., Ghesti, G. F., De Macedo, J. L., … Dias, J. A. (2017). Acidity and characterization of 12-tungstophosphoric acid supported on silica-alumina. Journal of the Brazilian Chemical Society, 28(2), 336–347. https://doi.org/10.5935/0103-5053.20160183
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