Effect of Amine Surface Coverage on the Co-Adsorption of CO2 and Water: Spectral Deconvolution of Adsorbed Species
Effect of Amine Surface Coverage on the Co-Adsorption of CO2 and Water: Spectral Deconvolution of Adsorbed Species
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DOI：
10.1021/jz502032c
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发表时间：
2014-12-04
影响因子：
5.7
通讯作者：
Jones, Christopher W.
中科院分区：
文献类型：
--
作者：
Didas, Stephanie A.;Salcwa-Novak, Miles A.;Jones, Christopher W.
三个伯胺材料功能化到介孔二氧化硅与低，中，高表面胺覆盖率的制备和评价二元CO2/H2O吸附在稀条件下。由于潮湿吸附的胺效率的增强对于低表面胺覆盖率的材料是最显著的。原位FT-IR光谱吸附CO2对这些材料表明，这种增强可能与形成碳酸氢盐物种在吸附过程中的材料与低表面胺覆盖率，虽然这样的物种没有观察到高表面覆盖率的材料。在具有最低胺负载的材料上，在较长的吸附时间尺度上观察到碳酸氢盐，但仅在除去快速形成的烷基氨基甲酸铵物种的光谱贡献之后。这是第一次，碳酸氢盐形成的直接证据，这是已知的发生在液体胺水溶液中，已经提出了固体胺吸附剂上的CO2吸附。
Three primary amine materials functionalized onto mesoporous silica with low, medium, and high surface amine coverages are prepared and evaluated for binary CO2/H2O adsorption under dilute conditions. Enhancement of amine efficiency due to humid adsorption is most pronounced for low surface amine coverage materials. In situ FT-IR spectra of adsorbed CO2 on these materials suggest this enhancement may be associated with the formation of bicarbonate species during adsorption on materials with low surface amine coverage, though such species are not observed on high surface coverage materials. On the materials with the lowest amine loading, bicarbonate is observed on longer time scales of adsorption, but only after spectral contributions from rapidly forming alkylammonium carbamate species are removed. This is the first time that direct evidence for bicarbonate formation, which is known to occur in liquid aqueous amine solutions, has been presented for CO2 adsorption on solid amine adsorbents.