Metal-impregnated zeolite Y as efficient catalyst for the direct carbonation of glycerol with CO2

Metal-impregnated zeolite Y catalysts were prepared by treatment of a NaY zeolite with an aqueous solution of AgNO3, Zn(NO3)(2) and SnCl2, followed by water evaporation. The materials were then calcined in air at 450 degrees C and evaluated in the reaction of CO2 with glycerol at 180 degrees C for 3 h at 100 Bar. The parent NaY zeolite was inactive under these conditions, but the metal-impregnated zeolites, as well as the calcined salt precursors, showed yields of glycerol carbonate up to 5.8%. The TON of the zeolite catalysts were significantly higher than that of the calcined salts, suggesting the formation of a highly active metal oxide phase at the external surface of the zeolite. (C) 2014 Elsevier B.V. All rights reserved.