Solid-state synthesis of alkaline lithium ceramics for integrated CO2 capture and conversion to syngas

Integrating CO 2 capture and utilization (ICCU) in the production of syngas for the C1 chemical industry through ICCU-RWGS (reverse water–gas shift reaction) is a vital strategy for achieving carbon reduction, and designing highly active dual-functional materials (DFMs) capable of CO 2 adsorption and in-situ conversion is crucial. Alkaline lithium ceramics with high availability, featuring high CO 2 capture and catalytic performance, are promising DFMs candidates for ICCU-RWGS. Herein, lithium ceramics of Li 5 FeO 4, Li 6 CoO 4 and Li 6 ZnO 4 were prepared via solid state synthesis as potential DFMs for ICCU-RWGS applications, and structure-property-activity relationships of the lithium ceramics DFMs in ICCU were discussed. The Li-Zn sample with high surface basicity and high density and uniform dispersion of active sites demonstrated a high CO 2 uptake (7.71 mmol CO 2 /g), CO yield (6.52 mmol CO/g), CO 2 conversion (84.9 %) and CO selectivity (∼100 %) as well as moderate CO 2 adsorption and hydrogenation kinetics at 650 °C, 10 %CO 2 and 40 %H 2 , making it a promising candidate for ICCU-RWGS. However, the Li-Zn DFMs exhibited poor cyclic ICCU-RWGS working stability due to lithium sublimation and crystal sintering at high temperatures, which deserves more future efforts to solve the dilemma. Our findings provide valuable insights into designing cost-effective DFMs for ICCU applications.