采用CaO基吸附剂的钙循环技术对于从烟气中捕获CO2至关重要。然而,CaO基吸附剂固有的低热力学稳定性和必要的成型步骤引起严重的烧结问题,降低了它们的循环稳定性。在这里,介绍了一种以熵稳定化和协同效应为前提的高熵萤石氧化物(HEFO)惰性稳定剂。HEFO改性,CaO基吸附剂颗粒是通过快速烟头辅助燃烧过程(15分钟)与石墨成型方法结合合成的。多周期后,它们的CO2捕获能力达到0.373g-1,比纯CaO高2.6倍,表现出显着增强的抗烧结性能。首先,微妙的形态和晶体学修饰表明,HEFO的固有熵稳定性赋予了强大的耐热性。同时,单相HEFO的无序结构对CaO具有很高的亲和力,导致-1.83eV的界面结合能,与纯CaO的-0.112eV形成鲜明对比,从而限制CaO迁移。此外,HEFO的多元素协同作用使能垒降低0.15eV,导致碳酸化和煅烧率增加40%和140%,分别。这项工作提出了高效和快速合成的CaO基吸附剂颗粒,展示了工业应用的潜力。
The calcium looping technology employing CaO-based sorbents is pivotal for capturing CO2 from flue gas. However, the intrinsic low thermodynamic stability of CaO-based sorbents and the requisite molding step induce severe sintering issues, diminishing their cyclic stability. Herein, a high-entropy fluorite oxide (HEFO) inert stabilizer premised on entropy stabilization and synergistic effect strategies is introduced. HEFO-modified, CaO-based sorbent pellets are synthesized via a rapid cigarette butt-assisted combustion process (15 min) combined with the graphite molding method. Post-multiple cycles, their CO2 capture capacity reaches 0.373 g g-1, which is 2.6-fold superior to that of pure CaO, demonstrating markedly enhanced anti-sintering properties. First, the subtle morphological and crystallographic modifications suggest that the inherent entropy stability of HEFO imparts robust thermal resistance. Concurrently, the disordered structure of single-phase HEFO exhibits a high affinity for CaO, resulting in an interface binding energy of -1.83 eV, in sharp contrast to the -0.112 eV of pure CaO, thereby restricting CaO migration. Additionally, the multi-element synergistic effect of HEFO reduces the energy barrier by 0.15 eV, leading to a 40% and 140% increase in carbonation and calcination rates, respectively. This work presents highly efficient and rapidly synthesized CaO-based sorbent pellets, showcasing promising potential for industrial application.