Preparation of Novel Li 4 SiO 4 Sorbents with Superior Performance at Low CO 2 Concentration

This work produced Li 4 SiO 4 sorbents through an impregnated‐suspension method to overcome its typical poor performance at low CO 2 concentrations. A SiO 2 colloidal solution and two different organic lithium precursors were selected. A bulgy surface morphology (and thus, the significantly enlarged reacting surface area) was obtained for Li 4 SiO 4 , which contributed to the high absorption capacity. As a result, the capacity in cyclic tests at 15 vol % CO 2 was approximately 8 times higher than conventional Li 4 SiO 4 prepared through a solid‐state reaction. The phenomenon of a progressively increasing capacity (i.e., sustainable usage) was observed over the 40 cycles investigated, and this increasing trend continued to the last cycle. Correspondingly, over the course of the multicycle absorption/ desorption processes, the sorbents evolve from lacking porosity to having a high number of micron‐sized pores.