By means of high-throughput synthesis and screening techniques a search of new mixed metal oxide catalysts for the selective oxidation of isobutane to methacrolein has been conducted. In a first library design the oxide precursors of nine selected elements (V, Fe, Mo, Cr, Ta, Nb, Mn, Sb and Bi) have been combined by using a sol-gel recipe and the catalysts obtained have been screened for the dehydrogenation and selective/total oxidation properties. Afterwards, the most interesting combinations were studied in more detail by screening the complete triangular composition spreads. Optimal performance towards isobutene and methacrolein yield was found for Mo10V10Sb80Ox. Finally, the best catalysts were up-scaled to gram scale and tested in a continuous flow reactor unit equipped with four parallel reactors. The improved performance of the Mo10V10Sb80Ox catalyst compared to the other catalyst formulations was consistent with the measurements made in the high-throughput MS-screening setup. (C) 2004 Published by Elsevier B.V.