高比表面积炭基固体酸催化剂的制备及应用

Study on the preparation and application of a carbon-based solid-acid catalyst with high surface area

【目的】制备清洁环保且高效的高比表面积炭基固体酸催化剂。【方法】以椰壳基、木粉基、煤基3种活性炭为原料,通过重氮盐还原法制备催化剂,比较3种催化剂的理化性质及性能,以选择最佳的活性炭催化剂。探讨乙醇与油酸物质的量比、反应温度、反应时间、催化剂用量等因素对油酸酯化率的影响,确定油酸酯化反应的最佳条件。【结果】以煤基活性炭制备的催化剂磺酸密度最大(0.64mmol/g),其催化效果也最好,在反应6h后,油酸的酯化率可达69.7%。油酸酯化反应的最佳条件为:乙醇与油酸物质的量比10∶1,反应温度80℃,反应时间12h,催化剂用量为油酸质量的6%,在此条件下,油酸的酯化率可达87.3%。煤基磺化活性炭催化剂在油酸酯化反应中可以稳定地重复使用3次。【结论】以煤基活性炭为原料,用重氮盐还原法可制得高效廉价且清洁环保的炭基固体酸催化剂。

【Objective】 The present study aimed at preparing a new carbon-based solid acid catalyst with high surface area.【Method】 The catalyst was synthesized in an aryl diazonium salt reduction process using activated carbon as catalyst carrier and sulfonic group as active sites.The influence of activated carbon raw materials on the catalyst preparation was studied.The esterification reaction of oleic acid and ethanol was used to examine the activity of catalyst.The reaction conditions such as ethanol to oleic acid molar ratio,reaction temperature,reaction time and catalyst mass on the oleic acid conversion were studied.【Result】 The carbon catalyst from coal-based activated carbon had the highest sulfonic group density of 0.64 mmol/g and best catalytic performance for the esterification of oleic acid and ethanol.The best reaction conditions for oleic acid esterification was as follows：ethanol to oleic acid molar ratio 10∶1,reaction temperature 80 ℃,reaction time 12 h,the amount of catalyst was 6% of oleic acid.Under these conditions,oleic acid conversion was 87.3%.The catalyst from coal-based activated carbon could be used for 3 times without obvious deactivoction.【Conclusion】 The carbon-based solid acid catalyst with high surface area can be prepared through the diazonium salt reduction of coal-based activated carbon.