碳基固体酸催化剂的合成及其催化酯化性能

Synthesis of carbon-based solid acid and its catalytic activity for esterification

以桃核壳为原料合成了碳基固体酸催化剂。利用乙醇和乙酸的酯化反应为模型反应,考察了不同碳化温度、磺化温度和磺化时间对催化剂活性的影响。用TG分析催化剂的热稳定性,用SEM及搭载的能谱分析仪EDS考察了催化剂的外貌特征和表面元素分布。结果表明,在300℃碳化和98℃磺化4.5 h所得的催化剂活性最高,每克碳基固体酸催化剂负载的磺酸基团为2.1 mmol。在反应时间5 h、反应温度70℃、催化剂用量为冰乙酸和乙醇混合物总质量的2%和醇酸物质的量比为1.5:1时,冰醋酸转化率为70.84%。

A carbon-based solid acid catalyst was synthesized using peach stones as raw material. The effects of carbonization temperature, sulfonated temperature and sulphonation time on activity of the catalyst were investigated using esteritlcation between ethanol and acetic acid as the model reaction. Thermal stability and surface composition of the catalyst were measured by TG and SEM/EDS, respectively. The results showed that optimal catalytic activity was attained over the catalyst carbonized at 300℃, sulphonated at 98 ℃ for 4.5 h, with 2.1 mmol sulfonic groups on the surface of 1 g catalyst. Acetic acid conversion of 70.84% was obtained under the reaction condition as follows： catalyst dosage = 2% of the total mass of ethanol and acetic acid, ethanol-to-acetic-acid mole ratio of 1.5： 1, reaction temperature 70℃, reaction time 5 h.