Influence of cerium doping on CO2 capture of CaO-based sorbents

The CeO2-doped CaO-based sorbent was prepared by the homogeneous precipitation method using P123 as the soft template. The influence of CeO2 doping on the capture of CO2 was investigated. The CeO2 doping can promote the formation of surface oxygen species, and facilitate the carbonation reaction. The interactions in CaO-CeO2 lead to the electrons transfer from Ca to surface oxygen species. Moreover, when Ce ions are substituted by Ca ions, the charge neutrality is destroyed in the CeO2 crystal, which promotes the formation of oxygen vacancies and O2-. Ea is tested to be 28.1 kJ/mol for the carbonation reaction of pure CaO sorbent, while Ea decreases to the minimal value of 10.2 kJ/mol when adding CeO2 to CaO sorbent with a Ce/Ca molar ratio of 0.25. Also, the doping of CeO2 is beneficial to the high dispersion of CaO and prevention of CaO sintering. The Ce-doped sorbents exhibit a superior capture capacity and cyclic stability in carbonation/calcination cycles. © 2019, Science Press. All right reserved.