Microstructured rhodium catalysts for the partial oxidation of methane to syngas under pressure

Microstructured honeycomb catalysts made of rhodium were manufactured and tested in the partial oxidation of methane under different experimental conditions. Even at operating pressures of up to 1.2 MPa with oxygen and up to 2.0 MPa with air, the catalyst was not found to be adversely affected by the reaction heat caused by the total oxidation taking place at the catalyst inlet. The high thermal conductivity of rhodium contributes to a good heat distribution in the flow direction, which is reflected by significantly increased conversions and CO and H-2 selectivities compared to those obtained by using a stack of commercial Pt/Rh gauzes. Increasing catalyst temperatures lead to an increase in the syngas yield. However, the thermodynamic equilibrium of the reaction was not reached in the experiments. Deactivitation of the catalyst was not observed during experimental operation.