Mg–O–F Nanocomposite Catalysts Defend against Global Warming via the Efficient, Dynamic, and Rapid Capture of CO2 at Different Temperatures under Ambient Pressure

The utilization of Mg–O–F prepared from Mg(OH)2 mixed with different wt % of F in the form of (NH4F·HF), calcined at 400 and 500 °C, for efficient capture of CO2 is studied herein in a dynamic mode. Two different temperatures were applied using a slow rate of 20 mL·min–1 (100%) of CO2 passing through each sample for only 1 h. Using the thermogravimetry (TG)-temperature-programed desorption (TPD) technique, the captured amounts of CO2 at 5 °C were determined to be in the range of (39.6–103.9) and (28.9–82.1) mgCO2·g–1 for samples of Mg(OH)2 mixed with 20–50% F and calcined at 400 and 500 °C, respectively, whereas, at 30 °C, the capacity of CO2 captured is slightly decreased to be in the range of (32.2–89.4) and (20.9–55.5) mgCO2·g–1, respectively. The thermal decomposition of all prepared mixtures herein was examined by TG analysis. The obtained samples calcined at 400 and 500 °C were characterized by X-ray diffraction and surface area and porosity measurements. The total number of surface basic sites and their distribution over all samples was demonstrated using TG- and differential scanning calorimetry-TPD techniques using pyrrole as a probe molecule. Values of (ΔH) enthalpy changes corresponding to the desorption steps of CO2 were calculated for the most active adsorbent in this study, that is, Mg(OH)2 + 20% F, at 400 and 500 °C. This study's findings will inspire the simple preparation and economical design of nanocomposite CO2 sorbents for climate change mitigation under ambient conditions.