Solid adsorbents modified with N-containing functional groups have been extensively studied due to their excellent CO₂ adsorption performance. In this work, an adsorbent was obtained to capture CO₂ by impregnating polyethylenimine (PEI) into MCM-41 with a reserved template that had different alkyl chain lengths [myristyltrimethylammonium bromide (C14), cetyltrimethylammonium bromide (C16), and stearyltrimethylammonium bromide (C18)]. The thermogravimetric analysis, small-angle X-ray diffraction, N₂ adsorption–desorption, Fourier transform infrared (FTIR) spectroscopy analysis, and in situ FTIR spectra were employed to study the properties of adsorbents. The results showed that the template had been successfully introduced into the supports in the synthetic process, and the CO₂ adsorption performance was quite sensitive to the alkyl chain length of the template. Besides, the adsorbent with the template (C16) exhibited the highest CO₂ adsorption capacity (2.49 mmol/g) and amine utilization rate (0.28 mmol CO₂/mmol N) under 25 °C and pure CO₂. It is believed that the appropriate alkyl chain length of the template could act as an important role in the enhancement of PEI distribution and decrease the CO₂ transfer resistance, thereby improving the CO₂ adsorption capacity.

中文翻译：

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用于 CO2 吸附的氨基功能化扩孔 MCM-41：模板烷基链长度的影响

用含N官能团改性的固体吸附剂由于其优异的CO ₂吸附性能而被广泛研究。在这项工作中，通过将聚乙烯亚胺 (PEI) 浸渍到具有不同烷基链长度 [肉豆蔻基三甲基溴化铵 (C14)、十六烷基三甲基溴化铵 (C16) 和硬脂基三甲基溴化铵 (C18) 的保留模板的 MCM-41 中，获得了一种吸附剂来捕获 CO ₂ )]。热重分析，小角X射线衍射，N ₂吸附-解吸、傅里叶变换红外 (FTIR) 光谱分析和原位 FTIR 光谱用于研究吸附剂的性质。结果表明，在合成过程中成功地将模板引入到载体中，CO ₂吸附性能对模板的烷基链长非常敏感。此外，以C16为模板的吸附剂在25 ℃和纯CO ₂下表现出最高的CO ₂吸附容量（2.49 mmol/g）和胺利用率（0.28 mmol CO ₂ /mmol N） 。认为模板的适当烷基链长度可以在增强PEI分布和降低CO _{2中起重要作用}转移阻力，从而提高CO ₂吸附能力。