Publisher Summary Partial oxidation of methane (POM) on monolithic catalysts at short contact times is a promising process for designing compact syngas generators. As is demonstrated for Rh- or Pt- supported catalysts, the optimization of their performance requires process modeling based upon a detailed elementary step reaction mechanism verified for pure metals. For more complex active components such as Pt-promoted LaNiO3 /Ce-Zr-O etc, elucidation of such detailed elementary kinetics would require too extensive research. This chapter presents a verification of more simple approach to modeling of both steady-state and start-up performance based upon using the rate constants for the reactions of methane selective oxidation and reforming reactions estimated for small separate units of monolithic catalysts in nearly isothermal conditions. Two types of honeycomb monolithic substrates based on corundum (a hexagonal prism with a side of 40 mm and triangular channels with wall thickness of 0.2–0.3 mm) or fechraloy foil (cylindrer 50 mm diameter, 200–400 cpsi, 20 μm foil thickness) were used. The metal surface is protected by a thin (∼10 μm) nonporous layer of corundum supported by the dust blasting. The active component comprised of mixed LaNiO3/Ce-Zr-La-O oxides (up to 15 wt%) and Pt (up to 0.5 wt.%) was supported via washcoating and/or impregnation procedures followed by drying and calcination.