Evaporation-induced self-assembly of mesoporous zirconium silicates with tunable acidity and facile catalytic dehydration activity

• Zr4+ incorporated mesoporous silicate synthesized in one pot by EISA.
• Up to 15 wt% Zr loading achieved in Zr-EISA retaining mesoporosity.
• Zr-EISA contains both Lewis and Brønsted acid sites.
• Acid sites promote facile, selective isopropanol dehydration to propene.

Zirconium ions were incorporated into mesostructured silicate by evaporation-induced self-assembly (EISA) method without the addition of a mineral acid. Zr loadings up to 26.5 wt% were achieved. The BET surface area and the pore volume of the Zr-EISA samples are in the range of 818–614 m2/g and 1.2–1.01 cm3/g, respectively. Amorphous ordered pore structure was evident from HR-TEM images. Diffuse reflectance UV–Vis spectra reveal that a majority of the Zr exists as isolated framework species and impart Lewis acidity. Pyridine FTIR analysis revealed the presence of both Lewis and Brønsted acid sites in the Zr-EISA samples. The Zr-EISA materials exhibit excellent isopropanol dehydration activity with nearly total olefin selectivity characterized by a moderate activation energy (approximately 86 ± 1 kJ/mol).

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