CO2 capture studies using LDH

https://doi.org/10.1039/C9DT03913A

“Pristine Ca–Al-adamantanecarboxylate LDH was used instead of preformed MMOs to avoid CO₂ contamination. Freshly prepared LDH was loaded into a platinum pan and decomposed under an inert atmosphere (using 100 mL min⁻¹ N₂ [99.99% purity], 2 h, 700 °C, 10 °C min⁻¹). Once the decomposition was complete, the temperature was brought back to the desired capture temperature and the CO₂ (99.98% purity) gas supply was switched on (for 2 h) to test the uptake capacity of the resultant MMOs. The cycling performance of the resultant MMOs was studied by conducting consecutive adsorption–desorption cycles at two different CO₂ concentrations (60 cycles at 86% CO₂ and 40 cycles at 14% CO₂). Adsorption cycles were performed at 600 °C for 30 min under a CO₂ atmosphere and desorption/regeneration was performed at 700 °C for 30 min under N₂. In a typical experiment, around 10 mg of the freshly prepared Ca–Al-adamantanecarboxylate LDH was placed in a platinum pan. The MMOs were first generated by decomposing the sample under a N₂ atmosphere at 700 °C for 2h (ramp 10 °C min⁻¹). After this step, the sample was brought back to the desired temperature (10 °C min⁻¹) under N₂ and the gas was switched to CO₂. The adsorption step was performed for 30 min under CO₂ and then the desorption step was carried out (30 min) by switching the gas to N₂ and increasing the temperature to 700 (10 °C min⁻¹).”