High-throughput experimentation in multicomponent bulk mixed metal oxides: Mo-V-Sb-Nb-O system for selective oxidation of propane to acrylic acid

The bulk mixed Mo-V-Sb-Nb oxides, which is a candidate catalytic system for the selective oxidation of propane to acrylic acid, were prepared using an automated synthesis workstation. Two catalyst compositions, Mo0.3V0.3Sb0.125Nb0.125 and Mo1.0V0.3Sb0.125Nb0.125, were characterized by XRD and Raman spectroscopy and shown to contain Mo6V9O40, Mo0.61-0.77V0.31-0.19Nb0.08-0.04Ox (a niobium-stabilized defect phase of a vanadium-rich molybdate), Mo3Nb2O11, and MoO3 as the major phases. The results of the structural characterization and kinetic screening demonstrated good reproducibility of the phase compositions and catalytic properties of the model Mo-V-Sb-Nb-O system and provided new insights into the transformation processes that occur in these mixed oxides with time on stream. These results suggest the promise of emerging high-throughput in situ characterization techniques for establishing fundamental structure-activity/selectivity relationships and developing novel multicomponent mixed metal oxides for selective oxidation of lower alkanes. (C) 2002 Elsevier Science B.V. All rights reserved.