Near 100% Co2 Conversion and Ch4 Selectivity in a Solid Oxide Electrolysis Cell with Integrated Catalyst

Direct methanation of CO 2 feed within a solid oxide electrolysis cell (SOEC) has been demonstrated in the literature. H 2 O splitting, CO 2 reduction, and the reverse water-gas shift are identified as the typical reaction principles that occur over an SOEC cathode. The introduction of a methanation catalyst component further shifts the product stream from syngas to methane.Two new catalyst implementation design strategies are proposed in this article. These strategies, along with proper selection of reaction conditions, have led to near 100% CO 2 conversion and near 100% CH 4 selectivity at 450°C for a CO 2 /H 2 O/H 2 feed over an yttria-stabilized zirconia (YSZ)-based SOEC cathode. Thermodynamic modeling indicates that the optimal configuration allows the system to reach thermodynamic equilibrium. Electrochemical testing confirmed that the cell function was not inhibited by these specific catalyst implementation methods