作者: Louise R. Smith , Paul J. Smith , Karl S. Mugford , Mark Douthwaite , Nicholas F. Dummer
DOI: 10.1039/C8CY02214C
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摘要: Aqueous glycerol solutions of up to 50 wt% were reacted over magnesium oxide catalysts at temperatures greater than 300 °C, the reactivity which was compared catalyst-free reactions. Under conditions, modest levels dehydration hydroxyacetone observed >400 °C in a steel reactor tube and >320 silicon carbide. For reactions MgO, product distribution becomes more diverse, resulting formation methanol, acetaldehyde, ethylene glycol, 1,2-propanediol acetic acid. The methanol space–time–yield MgO catalyst samples (0.5 g) found be highest 400 (205 g h−1 kgcat−1) with solution glycerol, or concentration 10 wt%; 255 kgcat−1 0.1 catalyst. Despite high conversion achieved, stable 48 h, following decrease during initial 2 h reaction. Post-reaction characterisation revealed that level coking conversions (>90%) ≥120 mg gcat−1. carbon mass balance determined by GC analysis for typical reaction 75% so lost from only represents quantity missing carbon; typically <10%. also promote molecular weight products via condensation reactions, responsible remainder ca. 15%. Therefore, total organic content post-reaction mixture coke calculated 94% starting solution. We conclude surface directs however, results indicate conditions are crucial obtain optimum yields.