Abstract
A series of mesoporous vanadosilicate V-MCM-41 molecular sieves with variable Si/V ratios have been hydrothermally synthesized at pH = 10. These materials were investigated by powder X-ray diffraction (XRD), framework FTIR, diffuse reflectance UV−visible spectroscopy, nitrogen sorption measurement, scanning electron microscopy, transmission electron microscopy (TEM), thermogravimetric analysis, and differential thermal analysis. XRD and FTIR showed that the solid products had the MCM-41 structure and contained only atomically dispersed vanadium consistent with framework vanadium in V-MCM-41. Nitrogen sorption results showed that all of the materials had a uniform pore size distribution with pore size of around 3.0 nm. The crystallinity of V-MCM-41 decreased with an increase of the vanadium content. The hexagonal array structure of uniform pore size was observed by TEM. It proved that the pores were highly aligned. The catalytic activities of V-MCM-41 were tested in the partial oxidation of benzene by diluted hydrogen peroxide in a batch reactor. Phenol was the only liquid product. The catalytic activities of V-MCM-41 were more active than those supported on Y and β zeolite. In addition, the V/MCM-41 prepared with hydrothermal synthesis was more active than that prepared with impregnation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.