CO2 chemisorption and evidence of the CO oxidation–chemisorption mechanisms on sodium cobaltate

CO2—H2O Capture and Cyclability on Sodium Cobaltate at Low Temperatures (30–80 °C): Experimental and Theoretical Analysis

“…The hydroxylation process is confirmed by the second weight loss evidenced between 290 and 420 °C. Finally, at T ≥ 550 °C, samples presented the last weight decrement associated with superficial and bulk decarbonation processes and/or cobalt oxide reduction, as it has been previously reported …”

“…Complementarily, Na 2 CO 3 decomposition was analyzed by considering weight decrements at T > 500 °C. Nevertheless, it must be noted that at this temperature not only Na 2 CO 3 decomposes, as it has been reported that cobalt oxide is reduced on these physicochemical conditions, releasing O 2 . Thus, if all cobalt is reduced from Co 2 O 3 to CoO, weight decrement recorded corresponds both to CO 2 desorbed and O 2 released [reaction ]: …”

“…Sodium cobaltate (NaCoO 2 ) was synthesized by the solid‐state reaction method at 850 °C for 12 h. Sample was characterized, structurally and microstructurally, using XRD and nitrogen (N 2 ) adsorption–desorption (details of synthesis and characterization techniques are reported elsewhere) . Although sodium cobaltate sample was labeled as NaCoO 2 , its chemical composition was determined by elemental analysis, showing the following composition, Na 0.89 CoO 1.95 …”

“…Recently, this material has been probed as a possible CO 2 captor, showing that it is able to chemisorb up to , between 150 and 740 °C, producing Na 2 CO 3 and different cobalt oxides. In addition, its bifunctionality, as a catalyst in the CO oxidation reaction and subsequent CO 2 capture, has been reported . Furthermore, it was recently reported that Fe, Ni, or Cu addition into NaCoO 2 modifies its CO 2 chemisorption, where Fe presents higher CO 2 capture capacities, in comparison with pristine NaCoO 2 .…”

Alkali Metal CO2 Sorbents and the Resulting Metal Carbonates: Potential for Process Intensification of Sorption-Enhanced Steam Reforming

“…The evidence of catalytic activity of Na2ZrO3 was reported by Alcantar-Vazquez et al, 21 where CO was catalytically oxidized into CO2 and chemisorbed at T ≥ 200 °C with the processes apparently taking place simultaneously. Li2CuO2 104 , NaCoO2 105 and Li2ZrO3 106 were also reported to perform catalytic CO oxidation to CO2 and subsequent chemisorption of CO2. The CO-CO2 conversion in Li2CuO2 and NaCoO2 follows a double reaction Mars-van Krevelen mechanism.…”