Doping Li4SiO4 with K-, Mg-, Cr-, Ce, Y2O3, Gd2O3 or LaPO4

https://doi.org/10.3390/ijms20040928

“Wang et al. [49] prepared K-, Mg-, Cr-, and Ce-doped Li₄SiO₄ and found that Ce was the most difficultly doped into the Li₄SiO₄ crystal lattice among the four elements. However, Ce was the most effective to inhibit the aggregation of Li₄SiO₄ grains, so Ce-doped Li₄SiO₄ achieved the highest CO₂ absorption performance. Subha et al. [50] studied the CO₂ absorption by Li₄SiO₄ material doped with Y₂O₃, Gd₂O₃ or LaPO₄, and found that both Y₂O₃ and Gd₂O₃ improved the CO₂ absorption capacity of Li₄SiO₄, and Y₂O₃-doped Li₄SiO₄ retained the highest CO₂ absorption capacity due to the segregation of second phase created by the doped unreacted Y₂O₃. Chen et al. [51] reported that Ca-doped Li₄SiO₄ material achieved high CO₂ absorption capacity and they proposed a modified double-shell mechanism to describe the CO₂ absorption and regeneration mechanism of Ca-doped Li₄SiO₄ as shown in Figure 9. The transformation of Ca₂SiO₄ to Li₂CaSiO₄ during CO₂ absorption process was beneficial of transferring CO₂ from Li₄SiO₄ surface to the core, which reduced the diffusion resistance and improved CO₂ absorption, and regeneration was also correspondingly enhanced.”

“Figure 9. CO₂ absorption and regeneration mechanism of Ca-doped Li₄SiO₄ [51].”