National Energy Technology Laboratory, United States Department of Energy, Pittsburgh, Pennsylvania 15236, USA.
Phys Chem Chem Phys. 2013 Jun 28;15(24):9752-60. doi: 10.1039/c3cp51101d. Epub 2013 May 14.
The structural, electronic, and phonon properties of Li8ZrO6 are investigated with the application of density functional theory and lattice phonon dynamics. Based on the calculated data, the thermodynamics of CO2 absorption-desorption for Li8ZrO6 is analyzed and compared with those of Li2ZrO3 and Li6Zr2O7. The band gap of Li8ZrO6 is indirect along Γ-L with a value of 4.74 eV. From the calculated thermodynamic properties of Li8ZrO6 reacting with CO2, we found that Li8ZrO6 could be regenerated at high temperatures (>1100 K). Our results indicated that the lithium zirconate with a lower Li2O/ZrO2 ratio has a lower turnover temperature. Hence, by mixing or doping two or more materials to form a new material, it is possible to find or synthesize CO2 sorbents that can fit the industrial needs for optimal performance. Although the CO2 capture capacity of Li8ZrO6 is much higher than that of Li2ZrO3, the high energy required for regeneration, the capacity loss during long absorption-desorption cycles, solid sintering at high temperature, and the material cost may affect its overall capture performance. Our results also provided some general guidelines for designing new CO2 sorbents.
采用密度泛函理论和晶格声子动力学研究了 Li8ZrO6 的结构、电子和声子性质。基于计算数据，分析并比较了 Li8ZrO6 对 CO2 的吸收-解吸热力学与 Li2ZrO3 和 Li6Zr2O7 的热力学。Li8ZrO6 的能带隙沿 Γ-L 为间接带隙，值为 4.74 eV。从 Li8ZrO6 与 CO2 反应的计算热力学性质可知，Li8ZrO6 可以在高温（>1100 K）下再生。我们的结果表明，具有较低 Li2O/ZrO2 比的氧化锂锆具有较低的转化温度。因此，通过混合或掺杂两种或更多种材料形成新材料，有可能找到或合成适合工业需求的 CO2 吸附剂，以实现最佳性能。尽管 Li8ZrO6 的 CO2 捕获容量远高于 Li2ZrO3，但再生所需的高能量、长时间吸收-解吸循环过程中的容量损失、高温下的固体烧结以及材料成本可能会影响其整体捕获性能。我们的结果还为设计新型 CO2 吸附剂提供了一些一般性指导原则。
