کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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42169 | 45913 | 2010 | 8 صفحه PDF | دانلود رایگان |
A series of zirconium doped MCM-41 silica supported WOx solid acid catalysts, with WO3 loading ranging from 5 to 25 wt%, has been prepared by impregnation with ammonium metatungstate, and subsequent activation at temperatures between 450 and 800 °C. XRD, Raman and UV–vis spectroscopies have allowed us to establish that at temperatures higher than 700 °C occurs the formation of (WO)x/ZrO2 nanoparticles on the surface of MCM-41 support, which exhibit acidic properties and are active in the esterification of oleic acid with methanol at 65 °C. WO3 loadings of 15–20 wt%, after activation at 700 °C, lead to the most active catalysts, with conversion values close to 100%. The catalyst with 15 wt% WO3 is stable even when the reaction is carried out at 200 °C, reusable at least during four cycles and no leaching of tungsten species in the liquid phase was found.
A series of zirconium doped MCM-41 silica supported WOx solid acid catalysts were prepared and characterized. XRD and UV–vis spectroscopy have allowed us to establish that at temperatures higher than 700 °C occurs the formation of (WO)x/ZrO2 nanoparticles on the surface of MCM-41 support, which exhibit acidic properties and are very active in the esterification of oleic acid with methanol at 65 °C..Figure optionsDownload high-quality image (103 K)Download as PowerPoint slide
Journal: Applied Catalysis A: General - Volume 379, Issues 1–2, 15 May 2010, Pages 61–68