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

Abstract

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 CO2 capture capacity (0.64 g CO2/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 N2 physisorption measurement, respectively. The favorable CO2 capture characteristics of CaO-based sorbents were attributed to the CaZrO3 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.