Chitosan Immobilized by Bauxite as an Efficient Natural Catalyst for Condensation Reaction

Chitosan and bauxite as natural compounds were applied for the synthesis of chitosan/bauxite (CS/B) as heterogeneous catalyst and this novel catalyst was characterized using several techniques such as FTIR, XRD, FESEM, EDX, TEM, BET and TGA analysis. The as-synthesized catalyst showed more stability and specific surface area compared to those of starting materials. The CS/B catalyst was tested in the Knoevenagel condensation under various condition and the best yield was achieved in ethanol at room temperature. The advantage of CS/B is ecofriendly, thermal stability, low-cost preparation and simple work-up. Further, the as-synthesized catalyst can be recycled for four times and it can suggest benefit heterogeneous catalyst with high yield for the organic reaction. It is notable that the components of CS/B are completely natural materials, and this catalyst is the combination of organic and inorganic compounds with high advantages.