Abstrait

Preparation of sulfonated carbon catalyst from ptoluenesulfonic acid/fructose for the beckmann rearrangement of ketoximes

Hong-ping Zhang, Xue-wen Ma, Hong-fang Xiao, Kui-xiang Shen

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 H2O2 and then the sulfonation and cabonazation with concentrated sulfuric acid. FT-IR spectroscopy indicated that such carbon material consists of aromatic carbon sheets bearing -SO3H, -COOH and phenolic -OH groups. Notably, the addition of oxidation treatment in the preparation of carbon catalyst can obviously enhance the densities of -SO3H 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