一步炭化磺化法制备煤基固体酸催化剂及其表征Preparation of coal based solid acid catalyst by one-step carbonization sulfonation and its characterization

以胜利褐煤为原料，通过浓硫酸一步炭化磺化法制备煤基固体酸催化剂，以油酸和甲醇的酯化反应评价催化剂的催化活性。采用单因素实验考察了固液比、磺化温度、磺化时间对催化活性的影响。采用红外光谱、元素分析、BET、SEM、XRD、热重分析等对煤基固体酸催化剂进行表征。结果表明，当磺化温度为110 ℃、磺化时间为90 min、固液比为1∶ 17时，煤基固体酸催化剂具有最优的催化活性，其催化油酸和甲醇的酯化反应的酯化率达到93.50%。煤基固体酸催化剂为具有较低石墨化程度的无定形碳结构，磺酸基已成功键合到了碳基载体上，同时具有丰富的含氧官能团，其表面呈现密集孔结构，且以介孔为主。煤基固体酸催化剂在低于140 ℃时具有较好的热稳定性，重复使用5次后，催化酯化率为57.21%。 Using Shengli lignite as raw material, coal based solid acid catalyst was prepared by one-step carbonization sulfonation of concentrated sulfuric acid. The catalytic activity of the catalyst was evaluated by esterification reaction of oleic acid and methanol.The effects of solid-liquid ratio, sulfonation temperature and sulfonation time on the catalytic activity were investigated.The coal based solid acid catalyst was characterized by IR, EA, BET, SEM, XRD and TG-DTG.The results showed that when the sulfonation temperature was 110 ℃, the sulfonation time was 90 min, and the solid-liquid ratio was 1∶ 17, the coal based solid acid catalyst had the best catalytic activity with the esterification rate reaching 93.50%.The catalyst was amorphous carbon structure with low graphitization degree. The sulfonic acid group was successfully bonded to the carbon-based support. The catalyst had abundant oxygen-containing functional groups, and its surface presented dense pore structure, which was mainly mesoporous. The catalyst had better thermal stability below 140 ℃. After repeated use for 5 times, the esterification rate was 57.21%.