High-pressure CO2 capture was evaluated on Li8SiO6. Several different high-pressure experiments were performed using CO2, and the sample products were analyzed using XRD, N-2 adsorption, SEM and DSC. The results clearly showed that CO2 is chemically and physically trapped and that the CO2 chemisorption improved as a function of temperature. Depending on the temperature, Li8SiO6 reacted with 2 mol or less of CO2 to produce an external shell composed of Li4SiO4, Li2CO3 and Li2O in a non-stoichiometric reaction. Independently of the external shell composition, the final surface area and pore volume increased independent of the external shell composition and favored the second sorption process: CO2 adsorption. Therefore, high pressures enhance CO2 capture between 30 and 350 degrees C, promoting the chemisorption and adsorption processes. (C) 2014 Elsevier B.V. All rights reserved.