Keggin heteropolyacids as new poly-functional catalysts in dihydropyrimidine synthesis and sulfide oxidation

G. SATHICQ, V. PALERMO, G. ROMANELLI, H. THOMAS, P. VÁZQUEZ.

Rosario

Workshop; 1er Taller de Ciencia Medio Ambiental en Rosario.; 2009

Since of their excellent characteristic, bulk heteropolyacids with Keggin structure (HPA) are widely used in industrial catalysis. These HPA are well known as oxidation and acid catalysts in which the red-ox and acid-based properties can be tuned by variation of the central heteroatom and addenda or transition metal-substituted atoms. The design of practical catalyst at atomic or molecular level has long been pursed, since precisely designed multifunctional catalysts are obviously desirable. Currently there is considerable interest in exploring the structure of catalyst precursor and the multicenter active sites to facility catalysis by HPA. In this research, we report the preparation of Bi and Bi-V Keggin structure where one Mo by one Bi and 0.5 of Bi and V, respectively, in molybdophosphoric acid (PM) was substituted. These catalysts were well characterized by means of FT-IR, 31P-NMR, DRS, XRD, SEM-EDS, thermal analysis and potentiometric titration. V and Bi heteroatom?s amount were estimated by ICP-AES analysis.