A facile Solvent/Nonsolvent Preparation of Sintering-Resistant MgO/CaO Composites for High-Temperature CO2 Capture

Abstract For CaO‐based high‐temperature CO 2 sorbents, excellent cyclic stability is highly desired for its practical applications. Among all techniques, preparation of CaO‐based composites is one of the most widely accepted strategies, and the mixing status between CaO and the inert supporting material is crucial for its anti‐sintering property. This work provides a new strategy for preparing nanometrically dispersed MgO/CaO composites with significantly improved cyclic stability. The so called solvent/nonsolvent synthesis method can endow a simultaneous solidification of Ca and Mg and result in a nano‐meter level mixing of CaO and MgO. The optimized sorbent Mg/Ca‐0.2 retained 95.3 % (13.45 mmol g −1 ) of its initial capacity after 7 cycles, while the control CaAc 2 −CaO only retained 52.9 % (8.67 mmol g −1 ) of its initial capacity. The addition of MgO also increase the CO 2 sorption and desorption kinetics after several cycles. We believe that this new and facile solvent/nonsolvent synthesis method is also promising for the preparation of other highly mixed metal oxides.