Carbon dioxide (CO2) capture is a process that can significantly reduce the amount of CO2 in the atmosphere. In this study, several solid sorbents were examined for their CO2 capturing performance over 30 carbonation-calcination cycles. The sorbents included natural calcined Cadomin limestone (denoted as CD), hydrated calcined Cadomin pellets (denoted as CP), core/shell sorbets with CD and CP as cores, and mesostructured silica (denoted as CD@Si and CP@Si, respectively) and titania (denoted as CD@Ti and CP@Ti) as shells. The core/shell sorbents were prepared with a protective porous shell using the mesoporous silica and titania layers. The surface morphology and porosity of all sorbents were qualified using scanning electron microscopy and were quantified using nitrogen physisorption. X-ray diffraction was also used to identify the crystal phase composition of the sorbents before and after calcination. The CP@Ti pellets showed the best performance in the retention of CO2 uptake over 30 cycles with an activity loss of 50.9%. This is attributed to the formation of a protective layer of thermally stable mesoporous titania using a sol-gel method, which prevented the aggregation of CaO crystals and sorbent sintering. Although the modified core/shell sorbents exhibited an improvement in maintaining the stability of the cyclic operation compared to natural limestone, further study is needed to understand the core/shell sintering phenomenon at high temperatures using other novel materials.