Synthesis of hierarchical Li4SiO4 nanoparticles/flakers composite from vermiculite/MCM-41 hybrid with improved CO2 capture performance under different CO2 concentrations

Abstract

Abstract Li4SiO4 is a type of very promising high-temperature CO2 sorbent, but suffers from poor cycling stability and low CO2 uptake under relatively low CO2 concentrations. In this contribution, we synthesized hierarchical Li4SiO4 nanoparticles/flakers composite from vermiculite/MCM-41 hybrid precursor and demonstrated these hybrid-type sorbents possess improved CO2 capture performance under different CO2 concentrations. The structural and morphological properties of synthesized n-(VER/MCM-41) (n\u202f=\u202f1, 2, 3) precursors and the resulting Li4SiO4-based sorbents n-(VER/MCM-41)-Li4SiO4 were carefully characterized using XRD, SEM, BET, and XRF. Then the CO2 uptakes and CO2 sorption kinetics of n-(VER/MCM-41)-Li4SiO4 were evaluated at different temperatures (500–650\u202f°C). We also found that the n-(VER/MCM-41)-Li4SiO4 is much less affected by CO2 concentration. Finally, the regenerative property and thermal stability of n-(VER/MCM-41)-Li4SiO4, VER-Li4SiO4, and MCM-41-Li4SiO4 were compared. In all, we demonstrated this new Li4SiO4 possesses the merits of both MCM-41-Li4SiO4 and VER-Li4SiO4 including high CO2 uptake, less effected by CO2 concentration, fast CO2 capture kinetics, and excellent cycling stability.