Abstract

Investigations into structure and properties of heteropolyoxomolybdates (HPOM) supported on nanostructured silica SBA-15 for the selective oxidation of propene are presented. H 4[PVMo 11O 40] Keggin ions supported on SBA-15 (PVMo 11-SBA-15) were prepared by incipient wetness of silica SBA-15 with suitable precursor solutions. Structure and properties of the resulting material were studied ex situ by X-ray diffraction and nitrogen physisorption measurements and in situ by combined X-ray absorption spectroscopy (XAS) and mass spectrometry under various reaction conditions. The characteristic structure of PVMo 11-SBA-15 and its evolution under reactive gas atmosphere are compared to that of bulk H 4[PVMo 11O 40]⋅ xH 2O. Structural investigations of as-prepared PVMo 11-SBA-15 have shown that the respective Keggin ions can be readily supported on silica SBA-15. In situ XAS measurements under reducing or oxidizing conditions revealed a pronounced support interaction effect. This effect resulted in a further decreased thermal stability of the supported Keggin ions compared to bulk H 4[PVMo 11O 40]⋅ xH 2O. Apparently, no stable HPOM Keggin ions could be obtained on silica SBA-15 under reaction conditions. However, in spite of their low thermal stability, HPOM supported on SBA-15 remain suitable well-defined precursors for preparing mixed oxide model catalysts for selective oxidation reactions.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

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.