Abstract:

Two series of catalysts, HPW/AC and TEAPW/AC, were prepared by impregnating tungstophosphoric acid and [TEAH]₃PW₁₂O₄₀ solution on active carbon. The structure and acidic property of these catalysts were characterized by IR, XRD, N₂ adsorption-desorption and NH₃-TPD techniques. Then these catalysts were used to catalyze the synthesis of 2-methacryloyloxyethyl phosphate, a functional phosphate, by using P₂O₅ as phosphorylation agent. These catalysts possess not only high activity but also high selectivity for the mono(2-methacryloyloxyethyl) phosphate since the formations of di(2-methacryloyloxyethyl) phosphate and tri(2-methacryloyloxyethyl) phosphate are restricted by the micropores of catalysts. Under the optimum conditions and on the optimal catalyst, the total ester yield and the selectivity of mono(2-methacryloyloxyethyl) phosphate are 94% and 95%, respectively. The catalyst can be isolated and recycled with high stability. This catalytic process not only avoids using chlorine-containing reagent in the synthesis, but also greatly increases monophoshpate content in the product.

Key words: phosphate, polyoxometalates, catalysts, catalytic synthesis