Effect of post-calcination thermal treatment on acid properties and pores structure of a mesoporous niobium–tungsten oxide

Effect of post-calcination thermal treatment on acid properties and pores structure of a mesoporous niobium–tungsten oxide was examined. Mesoporous Nb–W oxides treated by high temperature calcination from 673 up to 873 K exhibited a significant increase in pore size from 4.8 to 9.2 nm, a decrease in pore volume, surface area and acid amount, while the acid strength and density remained almost constant. A remarkable improvement in acid catalysis was observed for Friedel–Crafts alkylation and hydrolysis of disaccharide where the turnover frequency for both reactions increased continuously with calcination temperature.

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► Mesoporous Nb–W oxides treated by high temperature calcination.
► A significant increase in pore size and a decrease in pore volume, surface area, acid amount by the calcination.
► The acid strength and density remained almost constant.
► The turnover frequency for both Friedel–Crafts alkylation and hydrolysis increased with calcination temperature.