Incorporation of Zr into Calcium Oxide for CO2 Capture by a Simple and Facile Sol–Gel Method

A series of Zr-doped CaO-based sorbents were synthesized by a simple and facile sol–gel method, and sample of Ca/Zr (30:1) exhibited excellent CO 2 capture capacity (0.64 g CO 2 /g sorbent) and favorable stability (up to 18 cycles). The performance of sorbent still remained stable when tested under a high decarbonation temperature of 900 °C. The structure–property relationship of the sorbents was explored by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), and N 2 physisorption measurement, respectively. The favorable CO 2 capture characteristics of CaO-based sorbents were attributed to the CaZrO 3 nanoparticles, which created an inert barrier preventing the sintering–agglomeration, the nanosize of the particles, optimized pore size distributions, and uniform distribution of Ca and Zr in the sorbent.