FTIR study of 尾-picoline and pyridine-3-carbaldehyde transformation on V-Ti-O catalysts. The effect of sulfate content on 尾-picoline oxidation into nicotinic acid

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• 作者：Yuriy A. Chesalov ; Tamara V. Andrushkevich ; Vladimir I. Sobolev ; Galina B. Chernobay
• 关键词：Vanadia&ndash ; titania catalysts ; Sulfates ; 尾-Picoline oxidation ; Nicotinic acid ; FTIR spectroscopy
• 刊名：Journal of Molecular Catalysis A: Chemical
• 出版年：December, 2013
• 年：2013
• 卷：380
• 期：Complete
• 页码：118-130
• 全文大小：1547 K

文摘

Surface complexes of 尾-picoline, 3-pyridine-carbaldehyde and nicotinic acid on 20 wt.% V₂O₅/TiO₂ catalysts containing 0.07 and 6.3l wt.% SO₄^{2鈭?/sup> were studied by FTIR spectroscopy and temperature programmed reaction technique. The water (both H₂O and D₂O), pyridine and 尾-picoline were used as molecular probes for identification of surface acidity and the structure of sulfate species. Both samples possess Lewis and Br枚nsted acidic sites. 尾-Picoline, 3-pyridine-carbaldehyde and nicotinic acid form surface complexes of similar structure on both studied catalysts. But high sulfated catalyst contains stronger Br枚nsted sites in greater amount. It leads to the formation of stronger bound surface complexes of 尾-picoline, 3-pyridine-carbaldehyde and nicotinic acid. The strongly bound surface complexes are transformed into by-products (CO_x, pyridine and 3-cyanopyridine). It resulted in substantial reduction of nicotinic acid yield.}