A combinatorial search for novel catalysts for the oxidative dehydrogenation (ODH) of n-butane is presented. Nine hundred and fifty mixed oxides based on SiO2, TiO2, ZrO2 and Al2O3 have been prepared on a milligram scale using a pipetting robot. These materials have been screened for catalytic activity for the ODH reaction of ethylbenzene and n-butane by means of emissivity-corrected IR thermography. Selected active materials have been synthesised on a gram scale and tested in a conventional fixed bed reactor. A parameter optimisation study using a factorial design and data visualisation software revealed several regions of operability, where high selectivities and good yields were obtained. The best new catalyst found, Hf3Y3Ti94Ox, reaches a butene selectivity of 75% at 15% conversion at 450degreesC and ambient pressure, which compares well with state-of-the-art catalysts for this reaction. (C) 2003 Elsevier B.V. All rights reserved.