The use of sorbents capable of capturing high-temperature CO2 increases the overall efficiency of CO2 removal processes, without the need for cooling the flue gases. In this study, Na2ZrO3 for high-temperature CO2 sorption was newly prepared using a citrate sol–gel method. The characteristics and CO2 sorption behavior of the prepared Na2ZrO3 were examined by field-emission scanning electron microscopy, N2 adsorption analysis, X-ray diffraction, and thermogravimetric analysis, and compared with those of Na2ZrO3 synthesized using a conventional solid-state method. Na2ZrO3 could be synthesized at lower temperature by using the citrate sol–gel method compared to the case of solid-state method. Na2ZrO3 prepared using the citrate sol–gel method showed excellent CO2 sorption performance: high sorption capacity (17.5–21.0 wt % at 823 K and 1 bar), fast sorption kinetics, and good cycling stability. Kinetic analysis was also conducted by fitting the CO2 sorption behavior to the double exponential model.

中文翻译：

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柠檬酸盐溶胶-凝胶法制备高温CO2吸附用锆酸钠

使用能够捕获高温 CO2 的吸附剂可提高 CO2 去除过程的整体效率，而无需冷却烟气。在本研究中，使用柠檬酸盐溶胶-凝胶法新制备了用于高温 CO2 吸附的 Na2ZrO3。通过场发射扫描电子显微镜、N2 吸附分析、X 射线衍射和热重分析对制备的 Na2ZrO3 的特性和 CO2 吸附行为进行了研究，并与常规固态方法合成的 Na2ZrO3 进行了比较。与固相法相比，柠檬酸盐溶胶-凝胶法可以在较低温度下合成 Na2ZrO3。使用柠檬酸盐溶胶-凝胶法制备的 Na2ZrO3 表现出优异的 CO2 吸附性能：高吸附容量（在 823 K 和 1 bar 下为 17.5–21.0 wt%），吸附动力学快，循环稳定性好。还通过将 CO2 吸附行为拟合到双指数模型来进行动力学分析。