HT-search for alkaline- and noble-metal-free mixed oxide catalysts for soot oxidation

High-throughput techniques have been applied to search for soot oxidation catalysts free of noble metals and alkaline metals. Libraries consisting of up to 206 catalysts were screened for relative heats of reaction by emissivity-corrected infrared thermography. Using this approach, new catalyst formulations capable of combusting soot at relatively low temperatures were discovered. The hits identified via the high-throughput experimentation were successfully synthesized and tested conventionally using thermogravimetric analysis. The highest activity of the Pb10La5Co85Ox catalyst was found to be maintained after calcination at 700 °C. A good correlation between XRD and transmission electron microscope (TEM) measurements was achieved. Electron dispersive X-ray (EDX) analysis at specific points revealed a homogeneous distribution of the various constituents of the catalysts as expected based on the sol–gel method used.