Abstract The surface basicity and hydrophilic character of Mg and Al or Fe-based layered double hydroxides were assessed through thermal programmed desorption (TPD) of CO2 and H2O in terms of CO2 and water retention capacity (CRC and WRC), respectively. LDH calcination up to 450 °C produced slightly irreversible and detrimental effects on both properties, much less pronounced for Fe-based samples. These properties turned out to be completely revived after calcination below 200 °C. Iron-based LDH showed higher hydrophilic character but lower surface basicity than MgAl-2. Both CRC and WRC increased simultaneously with increasing PNLCO beyond a certain level. Water and CO2 adsorb via competitive interactions with weak to medium adsorption sites, but favor mutually their retention on strong basic sites. These results allow predicting LDH behavior in the adsorption of acidic gases and potential large-scale CO2 capture in humid conditions without previous dehydration.

中文翻译：

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MgAl 和 MgFe-LDH 对二氧化碳亲和力的新见解——亲水特性对 CO2 保留强度的作用

摘要 通过 CO2 和 H2O 的热程序解吸 (TPD) 分别在 CO2 和保水能力（CRC 和 WRC）方面评估了 Mg 和 Al 或 Fe 基层状双氢氧化物的表面碱度和亲水特性。高达 450 °C 的 LDH 煅烧对这两种性质产生了轻微的不可逆和不利影响，对于 Fe 基样品则不太明显。在低于 200 °C 的温度下煅烧后，这些性能完全恢复。与 MgAl-2 相比，铁基 LDH 具有更高的亲水性，但表面碱度更低。CRC 和 WRC 都随着 PNLCO 增加超过某个水平而同时增加。水和二氧化碳通过与弱到中等吸附位点的竞争性相互作用吸附，但有利于它们在强碱性位点上的保留。