Methods for Pt-WO₃/SBA-15 materials synthesis for glycerol conversion

Abstract

Glycerol has applications as a raw material in different industrial processes, however, its supply exceeds demand. An alternative to increase the added value of this feedstock is its conversion into high added-value chemical products through dehydration and hydrogenation reactions, from which 1,2-PDO and 1,3-PDO can be obtained. To develop catalysts that increase the conversion and selectivity of these processes, materials of 2% Pt and 10% WO₃ supported on SBA-15 were studied. Two methods were used for incipient wetness impregnation: sequential impregnation, with impregnation steps for each species, and co-impregnation, with a single impregnation step for both species. From the analysis of XRD, XRF, N₂ isotherms, SEM, EDS, FTIR, and pyridine FTIR spectroscopy, it was possible to observe the influence of these methods on the structural and textural properties. It was verified that the co-impregnation provided a better dispersion of the WO₃ species on the surface of the SBA-15 and that the reduction process, for both methodologies employed, showed an improvement in the metallic dispersion. The better dispersion of WO₃ species also resulted in a greater formation of Brønsted acid sites for the co-impregnation method, with a predominance of Lewis sites in the structure of the catalysts obtained by both methods.

Glycerol; SBA-15; wetness impregnation; mesoporous material