CO2 Electrolysis Using Metal-Supported Solid Oxide Cells with Infiltrated Pr0.5Sr0.4Mn0.2Fe0.8O3-δ Catalyst

Electrochemical conversion of CO2 to CO is demonstrated with symmetric-structured metal supported solid oxide cells (MS-SOC). Perovskite Pr0.5Sr0.4Mn0.2Fe0.8O3-delta (PSMF) and Pr6O11 catalysts were infiltrated into the MS-SOC cathode and anode, using 3 cycles with firing at 850 degrees C and 8 cycles with firing at 800 degrees C, respectively. Upon reduction during operation, the perovskite PSMF was transformed to Ruddlesden-Popper structure with a highly efficient electrocatalytic activity. The impact of operating temperature (600-800 degrees C) and overpotential (0-1.8 V) on the CO2 conversion was investigated. The highest CO2 conversion of 57.2% was achieved at 750 degrees C and 1.8 V. During extended operation for 150 h at 750 degrees C and 1.2 V, a cell demonstrated relatively stable performance, with initial current density of 535 mA cm-2 and CO2 conversion of 23%. Degradation mechanisms were studied by posttest characterization.