Facile Fabrication of Aluminum-Oxide Deposited Cuo/Cao Composites with Enhanced Stability and Co2 Capture Capacity for Combined Ca/Cu Looping Process

The combined Ca-Cu looping process is a promising CO 2 capture technology, in which the exothermic reduction of CuO with methane is used in situ to provide the heat required to calcine CaCO 3 . However, the CO 2 capture capacity of CaO/CuO composites decreases rapidly during multiple cycles. Herein, we proposed an aluminum-oxide deposited CaO/CuO composites synthesized by the space-confined chemical vapor deposition method and systematically investigated in accordance carbonation, calcinationreduction, and oxidation cycles. The deposited CaO/CuO composites feature highly porous structures and fine grain sizes, demonstrating significantly enhanced CO 2 capture performance with only 5 mol.% of Al stabilizer. The CO 2 absorption amount of Cu 1 CaAl 0.05 is 0.2183 g CO2 /g material in the first cycle. After 20 cycles, it still maintains 86.6% of the original absorption capacity, exceeding that of the undeposited CaO/CuO composites by 115%. Moreover, during the 20 cycles, the oxidation conversion of Cu 1 CaAl 0.05 always keeps above 95%, much higher than undeposited CaO/CuO composites. Various evidences indicate that the uniform deposition of aluminum-oxide on the CaO/CuO sorbent plays a vital role in improving the CO 2 absorption performance and cycling stability