Research progress of Na₂ZrO₃-based CO₂ sorbents for carbon capture from coal-fired flue gas

The iterative innovation of carbon capture and storage (CCS) technologies has laid a robust foundation for achieving the ‘3060’ dual-carbon targets. Among these advancements, fluidized bed reactor technology based on high-temperature solid sorbents stands out due to its exceptional compatibility with industrial flue gas systems and superior energy-economic efficiency, demonstrating strong application prospects for future CO₂ removal from flue gases. The Na₂ZrO₃-based sorbents, one of the high-temperature solid sorbents with outstanding cyclic stability and excellent CO₂ sorption performance—particularly under low-concentration CO₂ conditions—has shown significant engineering application value in carbon capture systems for hard-to-abate industries such as cement and metallurgy. This review systematically summarizes current research progress on Na₂ZrO₃-based sorbents for high-temperature CO₂ capture. Firstly, synthesis methods critically influence the physicochemical properties of Na₂ZrO₃ and employing milder wet-chemical routes and organic precursor modification can yield high-surface-area sorbents with enhanced gas-solid reactivity. Secondly, doping metal elements modifies the internal crystal lattice structure, impacting high-temperature CO₂ capture performance. Furthermore, advanced characterization techniques, sorption/desorption kinetic analysis, and density functional theory (DFT) calculations enable the description of CO₂ physisorption and chemisorption behavior across macro-, micro-, and atomic scales, facilitating the evaluation of various modification strategies. Finally, CO₂ capture performance under H₂O-contained atmospheres varies significantly across different temperature regimes. Future research should prioritize three key breakthroughs: (1) developing low-cost synthesis processes utilizing industrial solid waste for value-added adsorbent production; (2) investigating competitive sorption experiments of Na₂ZrO₃-based sorbents under complex gas components in real flue gas environments and elucidating CO₂ sorption/desorption mechanisms using multi-scale in-situ characterization and DFT; (3) addressing the high regeneration energy consumption to enable large-scale industrial deployment.