Enhanced carbon dioxide capture performance of natural mineral vermiculite‐derived lithium silicate with Na doping

Abstract Natural clay mineral‐derived functional materials have attracted considerable attention worldwide. Herein, natural mineral vermiculite (VMT)‐derived lithium silicate (VMT‐based Li 4 SiO 4 ) materials with different molar ratios of Na to Si were prepared for the high‐temperature CO 2 capture. Among developed adsorbents, the VMT‐Li 4 SiO 4 ‐2Na materials displayed superior CO 2 adsorption ability with 0.28 g/g adsorbent adsorption rate after 5 min and 33.67 wt% capture capacity at 650°C. The experimental investigations uncovered the presence of Li 3 NaSiO 4 or/and eutectic Li 2 CO 3 ‐Na 2 CO 3 molten salt resulting from the introduction of Na 2 CO 3 , which resulted in higher CO 2 uptake. Furthermore, the cyclic carbonation–decarbonation experiment of VMT‐Li 4 SiO 4 ‐2Na showed better stability when the O 2 was used to perform the decarbonation step. We believe that the Na modified‐VMT‐based Li 4 SiO 4 adsorbent shows potential for practical applications in peak carbon dioxide emissions and carbon neutralization. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.