Supported silicotungstic acid on zirconia catalyst for gas phase dehydration of glycerol to acrolein

• A series of supported HSiW on ZrO2 were screened for acrolein production.
• 69.3% acrolein selectivity at 93% glycerol conversion obtained by 30HZ sample.
• The 30HZ catalyst exhibited high stability even after 30 h.
• The optimum amount of Keggin anion density was 3.2 HSiW nm−2.

The gas phase dehydration of glycerol to acrolein over a series of supported silicotungstic acid (HSiW) on zirconia (10HZ, 20HZ, 30HZ and 40HZ) has been investigated. The catalysts were characterized by temperature programmed desorption, nitrogen adsorption–desorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy and energy dispersive X-ray techniques. The large pore diameters (>19 nm) of the prepared catalysts alleviated the coke deposition effect. Also, the specific surface area and acidity of the samples surged from 18 to 22 m2/g and 0.38 to 1.24 mmol/g cat, respectively by varying HSiW loadings from 10 to 40 wt% on zirconia. The highest acrolein yield achieved was 63.75% at 92% glycerol conversion over 30HZ catalyst for 10 wt% glycerol feed concentration and 300 °C reaction temperature in 3 h. The combined physico-chemical characteristics of 30HZ made it more superior compared with other samples in the current study.

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