Liquid phase esterification of acrylic acid with l-butanol catalyzed by solid acid catalysts

摘要

Esterification of acrylic acid with l-butanol has been studied in a heterogeneous solid-liquid reaction system using a variety of solid acids including an acidic salt of H_3PW_(12)O_(40), Cs_(2.5)H_(0.5)PW_(12)O_(40). The catalytic activity (per proton) of liquid acids such as heteropolyacids, H_2SO_4, and para-toluenesulfonic acid increased as the acid strength of the solution increased, but the difference in the activity among them was not significant. In the solid-liquid reaction system, Cs_(2.5)H_(0.5)PW_(12)O_(40) exhibited the highest catalytic activity in the unit of catalyst weight among the solid oxide catalysts, while the activity of Cs_(2.5)H_(0.5)PW_(12)O_(40) was less than those of so organic resins such as Nation and Amberlyst 15. Contrary to the liquid acids, the specific activity values (per proton) of solid acids were significantly different. It was demonstrated that the activity of Cs_(2.5)H_(0.5)PW_(12)O_(40) was almost retained after the addition of water, while the activities of the organic resins greatly decreased. The water-tolerant property of CS_(2.5)H_(0.5)PW_(12)O_(40) is presumed to be due to the hydrophobic nature of the surface.