Catalytic Partial Oxidation of Methane over Perovskite La4Sr8Ti12O38-δ Solid Oxide Fuel Cell (SOFC) Anode Material in an Oxygen-Permeable Membrane Reactor

The partial oxidation of methane to syngas over perovskite La 4 Sr 8 Ti 12 O 38-δ solid oxide fuel cell (SOFC) anode material was studied with a Ce 0.8 Sm 0.2 O 2-δ −La 0.8 Sr 0.2 CrO 3-δ dual-phase composite membrane reactor. The catalytic activity strongly depends upon both the reaction temperature and CH 4 feed rate or O 2 /CH 4 ratio. Approximately 88% CO and 89% H 2 selectivity at 30% CH 4 conversion can be achieved under the optimized membrane reactor operating conditions at 950 °C and CH 4 feed rate of 20 mL min −1 . Under more severe conditions at a higher CH 4 feed rate, La 4 Sr 8 Ti 12 O 38-δ in the membrane reactor exhibits favorable stability and a facile catalyst regeneration process against carbon deposition. The reaction mechanism is explored by a comparative study with a conventional fixed-bed reactor, suggesting a direct CH 4 partial oxidation route below 800 °C and obvious CO 2 and steam reforming activities above 850 °C. The reaction pathway would involve lattice oxygen species and a surface formaldehyde intermediate, which could explain the difference in the reactivity for both reactors. The possible application of this reaction in the membrane reactor was discussed with respect to the syngas production and characterization on the catalytic behavior of SOFC anode material for the direct methane fuel cell by simulating a SOFC anode operating environment.