In this paper, the porous MgAl-CO₃ LDHs-derived mixed oxides with Mg/Al molar ratios of 2:1, 2.5:1, 3:1, 3.5:1, and 4:1 have been successfully prepared by a facile solvothermal method. With a 3D nanoflower-like structure, the MgAl-CO₃ LDHs-derived mixed oxides with a Mg/Al molar ratio of 2 exhibit the best CO₂ sorption performance of about 0.9 mmol/g at the adsorption temperature of 200 °C. The addition of NaNO₃ into the MgAl-CO₃ LDHs-derived mixed oxides (Mg/Al = 2:1) can facilitate the sorption process by reducing the energy barrier between MgO and MgCO₃. Introducing methanol to the preparation process of LDHs prior to drying can effectively increase the specific surface area and improve the porosity of the sorbents by substituting the water molecules of MgAl-CO₃ LDHs. The sorbents co-modified by NaNO₃ and methanol with a Mg/Al molar ratio of 2 show the favorable sorption performance with the CO₂ uptake of 1.70 mmol/g over 100 sorption/desorption cycles about 300 h.

中文翻译：

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具有3D纳米花状结构的MgAl-CO ₃ LDHs衍生的吸附剂对CO _2的吸附

本文通过简便的溶剂热法成功制备了Mg / Al摩尔比为2：1、2.5：1、3：1、3.5：1和4：1的MgAl-CO ₃ LDHs多孔混合氧化物。方法。具有3D纳米花状结构，Mg / Al摩尔比为2的MgAl-CO ₃ LDHs衍生的混合氧化物在200°C的吸附温度下表现出约0.9 mmol / g的最佳CO ₂吸附性能。在源自MgAl-CO ₃ LDHs的混合氧化物（Mg / Al = 2：1）中添加NaNO ₃可以通过减少MgO和MgCO ₃之间的能垒来促进吸附过程。在干燥之前将甲醇引入LDHs的制备过程中，可以通过取代MgAl-CO ₃ LDHs的水分子来有效增加比表面积并改善吸附剂的孔隙率。NaNO ₃和甲醇以2的Mg / Al摩尔比共改性的吸附剂在约300 h的100个吸附/解吸循环中吸收1.70 mmol / g的CO ₂表现出良好的吸附性能。