| Summary: | 碩士 === 國立中正大學 === 化學工程所 === 96 === Nicotinic acid (NA) is the common form of the vitamin most often referred to as niacin (or vitamin B3). It enables the conversion of carbohydrates into energy as well as the metabolism of proteins and fats. The majority of niacin today is produced synthetically by chemical oxidation or ammoxidation of β-picoline.The supports are grafting VOx and TiO2 on spherical Silica in this research . The goals were to investigate the vanadai-titania interaction on VOx and TiO2 and their catalyzed effects and finds the best oprating conditions to produce nicotinic acid thereby exploring the high selectivity catalysts for commercial run. To adjust different operating variables including WHSV, the partial pressure of oxygen, the vapor flow and operating temperature and use catalysts VOx/TiO2/Silica、VOx/Silica and TiO2/VOx/Silica to do Partial oxidation of β-picoline to test the performance of catalysts. The structure of TiO2 and VO¬X can be characterized by the use of synchrotron powder X-ray and X-ray absorption spectroscopy. By detail analysis of EXAFS (extended X-ray absorption fine structure) spectroscopy the role of TiO2 on the structure of V2O5 has been clarified. The results indicated that crystalline anatase TiO2 and rutile TiO2 have been observed for catalysts, and the structure of VOx was altered by the calcination temperature and the grafted sequence. The crystalline anatase TiO2 anchor V2O5 clusters from migration thereby enhance the dispersion of VOX. In other hands, by test the performance of catalysts, the yield of produce nicotinic acid increase to 81.9% and the selectivity enhance to 87.9%.
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