Bifunctional application of sodium cobaltate as a catalyst and captor through CO oxidation and subsequent CO2 chemisorption processes

The potential bifunctional mechanism of sodium cobaltate (NaCoO2) in the catalysis of CO oxidation and subsequent CO2 chemisorption was systematically analysed. Different catalytic and gravimetric experiments were performed dynamically and isothermally at multiple temperatures. Initially, the CO oxidation process was evaluated using a catalytic reactor connected to a gas chromatograph. Once the production of CO2 was confirmed, its chemisorption capacity with NaCoO2 was studied gravimetrically. Catalytic and gravimetric analysis products were studied by XRD, FTIR and SEM to elucidate the double reaction mechanism. Sodium cobaltate exhibited interesting catalytic properties over a wide temperature range, although the NaCoO2 crystalline structure and chemical composition changed during the CO2 capture process. Furthermore, all the experiments were theoretically supported by first-principles density functional theory thermodynamic calculations. The calculated thermodynamic properties of the CO oxidation and CO2 capture reactions with NaCoO2 under different oxidation conditions were in good agreement with the experimental measurements.