基于果糖／对甲基苯磺酸磺化炭的制备、表征及酸催化性能

摘要

以果糖和对甲基苯磺酸为原料，通过聚合、双氧水氧化和浓硫酸磺化、碳化等步骤制备了磺化炭催化剂． FT－IR和TG－DTA分析表明：制备的磺化炭是一种富含－SO3 H，－OH，－COOH等基团并具有多环芳烃结构的无定型固体酸功能材料．将氧化和未氧化处理的磺化炭酸密度进行比较，双氧水氧化可以显著增加磺化炭中磺酸基和总酸含量，用离子交换－酸碱滴定法测得氧化后磺化炭中磺酸基含量为3．01 mmol g－1，总酸量为6．13 mmol g－1．在催化Beckmann重排反应中，这种富含亲水性基团的磺化炭具有良好的催化活性和重复使用性能．%A sulfonated carbon catalyst was conveniently prepared via multistep processes,involving the polymerization of fructose with p-toluene sulfonic acid (TsOH),followed by the oxidation with H2 O2 and then the sulfonation and cabonazation with concentrated sulfuric acid. FT-IR spectroscopy and thermogravimetry analyses indicated that such carbon material consists of aromatic carbon sheets bearing-SO3 H,-COOH and phenolic-OH groups. Notably,the addition of oxidation treatment in the preparation of carbon catalyst can obviously enhance the densities of-SO3 H groups (3. 01 mmolg-1 )and total H+ sites (6. 13 mmolg-1 ),as supported by thermogravimetry and chemical titration analyses. As a result,such catalyst with numerous hydrophilic groups showed a high catalytic activity and an excellent repeatability for the Beckmann rearrangement of hydrophilic ketoximes.