Abstract

A new synthesis route for sulfated zirconia and iron, manganese, and iron–manganese promoted sulfated zirconia has been investigated. Zirconium hydroxide precursors were prepared from hydrogel and hydro-alcogel; freeze-drying as well as oven-drying has been employed. The pure hydroxides, sulfated, and metal promoted sulfated zirconia were calcined at 650 °C and characterised by chemical analysis, XRD, TG/DTG/DTA, nitrogen adsorption, SEM, FTIR pyridine adsorption, and ammonia TPD. The catalytic activity of the samples was screened in the double bond isomerisation of 1-butene and the benzoylation of anisole.

Significant differences in the textural and acidic properties were found for samples prepared either by freeze- or oven-drying. Virtually no difference in acidity was observed between sulfated and metal promoted sulfated zirconia.

Freeze-drying, especially the hydro-alcogel synthesis, was found to be a powerful preparation method for promoted and unpromoted sulfated zirconia catalysts.