Glycerol acetylation on mesoporous KIL-2 supported sulphated zirconia catalysts

Abstract

Zirconia nanomaterials were prepared by impregnation of KIL-2 type silica with 4, 8 and 12 wt.% ZrO₂ and were modified by sulphate groups in order to vary the type and strength of acidity. Samples were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and N₂ physisorption methods. Acidic properties of adsorbed pyridine were investigated by FT-IR spectroscopy. The catalytic performance of ZrKIL-2 and SO₄²⁻/ZrKIL-2 in glycerol esterification with acetic acid was studied and compared to that of pure zirconia varieties. It was found that silica-supported zirconia samples are more active than pure zirconia ones. With increasing ZrO₂ content, KIL-2-supported catalysts showed increasing catalytic activity and selectivity in producing valuable fuel additives, di- and triacetyl glycerols. Sulphated analogues showed even higher activity and selectivity compared to non-sulphated ones due to their strong Brönsted acidity.