The electrochemical performance of six imidazolium cation-based ionic liquids (ILs) containing 0.3 mol L −1 Mg(CF 3 SO 3 ) 2 as the electrolytes for magnesium deposition-dissolution was examined by cyclic voltammogramms and constant current dischargecharge techniques. Scanning electron microscopy and energy dispersive X-ray spectroscopy measurements were conducted to characterize the morphologies and components of the deposits. The cathodic satiability of imidazolium cations can be improved by increasing the length of alkyls at the 1-position and introducing methyl group at the 2-position of the imidazolium cations. A reversible magnesium deposition-dissolution can be achieved at room temperature. After adding appreciate amount of tetrahydrofuran (THF) organic solvent, the conductivity and the peak currents for Mg deposition and dissolution can be significantly improved. The potential polarization of deposition-dissolution process is decreased using Mg powder electrode.

Potassium carbonate (K2CO3) is recognized as a potential candidate for CO2 capture by flue gas under moist conditions because of its high sorption capacity and low cost. However, undesirable effects and characteristics that are associated with the desorption process, such as the slow reaction rate and the high regeneration temperature, lead to high energy costs and thus hinder its application. To improve the CO2 capture properties of K2CO3 under moist conditions, we investigated in this study the reaction rate and the regeneration temperature of a K2CO3–carbon composite (KC-CC), which was prepared from terephthalic acid and KOH. The successful synthesis of KC-CC was confirmed by the X-ray diffraction and Raman spectrometry results, while the CO2 capture characteristics of KC-CC under moist conditions were examined by thermogravimetric analysis. The CO2 capture experiment was repeated twice. The CO2 capture by KC-CC was faster than that by bulk K2CO3, while after the CO2 capture, the regeneration proceeded at lower temperatures compared to bulk KHCO3. Moreover, after a 10-cycle repetition of the CO2 capture experiment, KC-CC exhibited a stable performance. Thus, compared to bulk K2CO3, KC-CC could efficiently capture CO2 at an increased reaction rate and a lower regeneration temperature. This may be due to the nanostructural properties of KC-CC, which were also indicated by the results of XRD analysis.

A Na2CO3–carbon nanocomposite (NaC-NC) was prepared from terephthalic acid and NaOH, and its CO2 capture under moist conditions was examined by thermogravimetric analysis and X-ray diffraction. CO2 capture was repeated twice. The first CO2 capture reaction of bulk Na2CO3 was faster than its second, while the second capture reaction of NaC-NC was faster than its first. This may be because of the nanostructural properties of NaC-NC. The regeneration from NaHCO3 to Na2CO3 of NaC-NC proceeded at a lower temperature than with the bulk NaHCO3. Thus, compared with the bulk Na2CO3, we found that NaC-NC could efficiently capture CO2, increasing the reaction rate and decreasing the regeneration temperature.

In this study, adsorbents containing Li were synthesized, which have excellent carbon dioxide adsorption capacity, adsorption selectivity and reproducibility, and have great application prospects in the field of CO2 adsorption.