Synthesis and characterization of 12-phosphotungstic acid supported on BEA zeolite

• Published in: Materials chemistry and physics Vol. 186; pp. 430 - 437
• Main Authors: Jović, A., Bajuk-Bogdanović, D., Nedić Vasiljević, B., Milojević-Rakić, M., Krajišnik, D., Dondur, V., Popa, A., Uskoković-Marković, S., Holclajtner-Antunović, I.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.01.2017; Elsevier BV
• Subjects: Catalysis; Catalytic activity; Chemical compounds; Chemical synthesis; Composite materials; Dehydration; Diffraction; Electron microscopy (SEM); Ethanol; Fourier transform infrared spectroscopy (FTIR); Infrared analysis; Molecules; Powder diffraction; Scanning electron microscopy; Spectrum analysis; Stress concentration; Strong interactions (field theory); Ultrasonic techniques; Zeta potential; Ultrasonic techniques; Electron microscopy (SEM); Powder diffraction; Composite materials; Fourier transform infrared spectroscopy (FTIR)
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2016.11.015

An optimized synthetic route for obtaining heteropoly acid (HPA) species supported on BEA zeolite was applied, and different samples, comprising 20 to 50 wt% of 12-phosphotungstic acid (HPW) were prepared. The as-synthesized supported HPW were subjected to different post-synthesis routes, which involved calcination and ultrasound treatment. Characterization of these materials was performed by means of Scanning Electron Microscopy, zeta potential measurements, Infrared Spectroscopy and X-ray Powder Diffraction analysis. Results suggest strong interaction of HPW with the support and revealed that ultrasound treatment resulted in better dispersion of active phase and thus homogeneous morphology of the samples. The zeta potential was found to be dependent on the preparation procedure and HPW content in these materials, while higher HPW loadings induced its agglomeration. Catalytic activity of the synthesized materials was investigated in an ethanol dehydration reaction, where lower HPW loadings induced higher ethanol conversion. Acid sites distribution and accessibility for ethanol molecules were found to be more essential for catalytic activity than HPW loadings, i.e., amount of active sites present in these hybrid materials. [Display omitted] •An optimized route for supporting heteropoly acid on beta zeolite is applied.•Ultrasound treatment of the composites gives dispersed morphology.•Lower heteropoly acid amount induces higher conversion in ethanol dehydration.•Acid sites distribution and accessibility for ethanol are essential for catalytic activity.