Development of Sn-ZSM-11 zeolites for the synthesis of alkyl lactates

Abstract

In the present work are exposed different alternatives of incorporation of Sn in zeolite ZSM-11 (structure MEL): wet impregnation, alkaline treatment and hydrothermal synthesis with tin as heteroatom; as well as different metallic cation content (~ 2-10% w / w). The ZSM-11 structure was confirmed by XRD for all samples, while in the impregnated materials the crystallinity decreased as the amount of metal incorporated in the catalyst increased. The TPR study indicated the reduction of the surface species neighboring the Sn-O bonds and the reduction of Sn+4to Sn+2. By the BET method the surface area was analyzed and it was found that it decreases with the increase of the Sn content incorporated by wet impregnation and by hydrothermal synthesis. By means of FTIR with pyridine adsorption, the quantity, strength and ratio of acidic sites were determined. The previously synthesized and characterized materials materials exhibited a good catalytic performance in the conversion of dihydroxyacetone (DHA) to short chain alkyl lactates, the latter representing promising green solvents.