Li4+x(Si1–xAlx)O4 Solid Solution Mechanosynthesis and Kinetic Analysis of the CO2 Chemisorption Process

Different Al-containing Li 4 SiO 4 samples (Li 4+ x (Si 1– x Al x )O 4 solid solutions) were obtained by mechanosynthesis and then characterized structurally (X-ray diffraction (XRD) and solid-state NMR) and microstructurally (N 2 adsorption and scanning electron microscopy (SEM)). While solid-state NMR results showed that the aluminum (silicon) presented some distortion after the milling process, the milling process tended to increase the Li 4+ x (Si 1– x Al x )O 4 surface areas. The samples were tested dynamically and isothermally in the CO 2 chemisorption at high temperatures. In the second case, a complete kinetic analysis was produced. It was evidenced that aluminum addition and the new microstructural features produced during the milling process importantly increase the CO 2 capture, in comparison to the Li 4 SiO 4 phase and the Li 4+ x (Si 1– x Al x )O 4 solid solutions prepared by solid-state reaction.