Preparation of Activated Carbon-SnO2, TiO2, and WO3 Catalysts. Study by FT-IR Spectroscopy

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• 作者：Adrián Barroso-Bogeat ; María Alexandre-Franco ; Carmen Fernández-González ; Antonio Macías-García ; Vicente Gómez-Serrano
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：May 11, 2016
• 年：2016
• 卷：55
• 期：18
• 页码：5200-5206
• 全文大小：361K
• 年卷期：0
• ISSN：1520-5045

文摘

The chemical changes produced in the surface of activated carbon as a result of the process of preparation of activated carbon–metal oxide catalysts from SnCl₂, TiO₂, and Na₂WO₄ in water at pH 1.37 for SnCl₂, 5.84 for TiO₂, and 9.54 for Na₂WO₄ are studied. The samples were first prepared by the wet impregnation method in two successive steps of soaking at 80 °C for 5 h and oven-drying at 120 °C for 24 h. Then, they were analyzed by elemental analysis, FT-IR spectroscopy, and measurement of pH of the point of zero charge (pH_pzc). The process yield was 149 wt % with SnCl₂, 103 wt % with TiO₂, and 106 wt % with Na₂WO₄. The impregnation of the carbon with the catalyst precursors in water entails the oxidation of chromene and pyrone type structures with formation of carboxylic acid groups. pH_pzc is 10.50, activated carbon; <1.60, SnCl₂; 9.35, TiO₂; and 7.90, Na₂WO₄. The changes originating in the surface chemistry of AC with influence on the acid–base character are stronger by the order SnCl₂ ≫ Na₂WO₄ > TiO₂.