Regeneration of Rh/Ce0.75Zr0.25O2 – δ/θ-Al2O3/FeCrAl Catalyst after Autothermal Reforming of Diesel Fuel

Abstract The formation of soot (coke) on the surface of a structured Rh/Ce0.75Zr0.25O2/Al2O3/FeCrAl catalyst in the course of autothermal reforming of diesel fuel into synthesis gas was studied. The SEM analysis revealed the formation of fibrous carbon particles of 5–50 µm in size on the catalyst surface. It was found that the process of coke formation occurred on the catalytic coating surface and caused no exfoliation and/or damage of the catalytic layer; the carbon deposits were readily oxidized during catalyst regeneration by oxygen or water vapor. Intense oxidation of soot with oxygen began at a temperature of 450°C; a major portion of carbon deposits was oxidized even before the reactor furnace reached an operating temperature of the autothermal reforming of diesel fuel (750°C). Water vapor also oxidized carbon deposits but less efficiently than oxygen. The catalyst regeneration with water vapor proceeded actively at a temperature of 750°C, and this fact indicated the possibility of catalyst self-regeneration in the autothermal reforming of diesel fuel, which is performed with an excess of water.