Preparation of a novel solid acid catalyst with Lewis and Brønsted acid sites and its application in acetalization

Authors: YIJUN DU, LINJUN SHAO, LINGYAN LUO, SI SHI, CHENZE QI

Abstract: A novel melamine--formaldehyde resin (MFR) supported solid acid with Lewis and Brønsted acid sites was synthesized through the immobilization of acidic ionic liquid and cuprous ion on MFR. The scanning electron microscopy (SEM) characterization showed that addition of PEG-2000 in the synthesis of MFR could promote the formation of regular particles with diameters around 3.7 \mu m. The XRD pattern demonstrated that some cuprous ions were aggregated. The catalytic performance of this acid catalyst was evaluated by acetalization. The results showed that the catalytic activity of MFR with Brønsted acid could be improved by addition of Lewis acid. The solid acid was very efficient for the acetalization of carbonyl compounds and diols with moderate to excellent yields and there was no loss of catalytic activity even after being recycled for 6 runs.

Keywords: Solid acid, acetalization, Brønsted acid, Lewis acid, cuprous ion

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