People have realized that CO2 is the main contributor to the greenhouse effect.The key for improving the situation is to control and capture the CO2 discharged by fossil fuel power plants [1].However,the current CO2 separation technologies could not be conducted until the high temperature flue gas was cooled below 100℃ [2].With the advantages of wide sources,low cost,easy preparation and regeneration,CaO becomes the suitable absorbent for CO2 at high temperature [3].In this study,aiming at the sintering problem of CaO through multiple carbonation and calcination,a kind of modified calcium-based absorbent was studied to capture CO2 from flue gas at high temperature by doping CeO2.The TGA was used to estimate the adsorption capacity of absorbents with different doping ratios of CeO2 at 700℃ in the 30vol% CO2 atmosphere.Ca/Ce(8:2),with the largest surface area(50.90m2/g),had the best performance in all doped absorbents.In the carbonation/calcination cycling experiments,pure CaCO3 had better performance in the first few cycles.But the adsorption capacity of Ca/Ce(8:2) had caught up with pure CaCO3 since the forth cycle and still kept well cycling stability (86.1%) after 20 cycles.The BET data,SEM and XRD images demonstrated that the appropriate doping ratio of CeO2 could structure a strong framework to obstruct the contact between CaO particles.The mesoporous were kept in good condition and sintering was almost prevented after multiple cycles at high temperature.Ca/Ce(8:2) would be an anticipated high temperature absorbent for capture CO2.Model fitting method was used to determine the kinetic model of Ca/Ce(8:2) to be f(a)=1-4(1-a))[-ln(1-a)]-3in the carbonation from 340℃ to 677℃ at the rate of 5℃/min.The activation energy is respectively 135.0kJ/mol and 207.2kJ/mol,corresponding to two stages,from 340℃ to 540℃ and from 550℃ to 677℃.The existence of CeO2 could reduce the decomposition temperature of CaCO3.