MWW-type catalysts for gas phase glycerol dehydration to acrolein

• MWW derived materials are active catalysts for gas phase glycerol dehydration.
• Higher acrolein selectivity is attained using ITQ-2.
• ITQ-2 can be successfully recycled by coke burning.
• Air co-feeding decreases deactivation by coke formation.
• ITQ-2 has proved to be a good candidate for a long-time stability catalyst.

The materials derived from MWW layered precursor (MCM-22, MCM-36 and ITQ-2) were synthesized with molar ratio SiO2/Al2O3 = 30, characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), textural analysis by N2 physisorption, temperature programmed desorption of ammonia (NH3-TPD) and diffuse reflectance infrared spectroscopy (DRIFTS) of adsorbed pyridine and evaluated in gas phase glycerol dehydration to acrolein. The delaminated material (ITQ-2) has presented better catalytic performance than MCM-22 zeolite or MCM-36 pillared material, in both glycerol conversion and acrolein selectivity. These results were interpreted based on the textural properties and acidity changes. ITQ-2 excellent performance is due to higher accessibility and improved acidity when compared to pillared MCM-36 or parent MCM-22 zeolite. Long-term stability under either nitrogen or air co-feeding was investigated for ITQ-2.

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