Amine functionalized K10 montmorillonite: a solid acid–base catalyst for the Knoevenagel condensation reaction

Abstract

Different amine functionalized K10 montmorillonites were hydrothermally fabricated by a simple method of treatment of the neat clay with different amine solutions and used as heterogeneous catalysts towards the Knoevenagel condensation reaction. Catalytic results show that the di-amine functionalized K10 montmorillonite exhibits high efficacy for promoting this reaction at room temperature and in the absence of a solvent. The solid catalyst was characterized using a variety of different techniques; including Fourier transform infrared spectroscopy (FT-IR), nitrogen physisorption measurements, ²⁹Si CP MAS NMR spectroscopy, NH₃-temperature programmed desorption (NH₃-TPD), X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FESEM). The catalyst could be recycled and reused for several runs without any loss of inherent catalytic activity.