Influence of the K‐, Na‐ and K‐Na‐carbonate additions during the CO 2 chemisorption on lithium oxosilicate (Li 8 SiO 6 )

Lithium oxosilicate (Li 8 SiO 6 ) was synthesized and mechanically mixed with potassium carbonate, sodium carbonate, or a mixture of both. While the product sample composition was characterized using X‐ray diffraction, the CO 2 chemisorption was evaluated using dynamic (30–800 °C), isothermal (350–650 °C) and cyclic thermogravimetric analyses. The presence of the K, Na, or K‐Na‐carbonates in Li 8 SiO 6 changes the sorption properties in a wide temperature range. K‐, Na‐, K‐Na‐Li 8 SiO 6 samples captured a maximum weight of 32 wt% at 400 °C, 42 wt% at 550 °C, and 38 wt% at 600 °C, respectively. The results revealed that the weight gained on Li 8 SiO 6 mixed with K‐, Na‐ and K‐Na‐carbonates was attributed to the formation of the eutectic phases. These materials would be suitable for CO 2 capture over a wide temperature range depending on the application process. Nevertheless, the cyclic experiments showed important variations in their respective efficiencies, depending on the temperature.