Synthesis of Keggin-type polyoxometalate crystals

Vanadium-containing polyoxometalates (POM) were synthesized under acidic conditions and characterized by XRD, FT-IR, 51V MAS-NMR, EXAFS-XANES and SEM.POM crystals were successfully grown under acidic atmosphere, thus forming a self-assembled structure. This self-organized structure was constituted by cubic crystals having between 20 and 80 μm in size.Both 51V MAS-NMR, EXAFS-XANES and PM6 calculations suggest that non-covalent interactions, such as hydrogen bonding, or shared vanadium atoms of non-complete coordination are the driving force of the self-assembly process.

This study reports an innovative approach to prepare polyoxometalates (POM) crystals. The novelty consists in achieving a microscopic design of these POM materials; hence to organize the tertiary structure of heteropolyacids in order to get a higher catalytic activity. Figure optionsDownload as PowerPoint slide