2024年2月常州大学低碳清洁能源与安全高效燃烧科研团队孙运兰教授课题组王佳欣博士在Journal of the Energy Institute期刊发表了题为“Ultrasonic-assisted preparation of organic amine-modified SBA-15 for CO₂ capture in wide temperature range: Experimental and computational investigation”的研究论文。

胺改性介孔硅吸附剂被广泛用于CO₂捕集，然而其吸附性能易受温度和湿度的影响。本文制备了四乙烯五胺（TEPA）改性的SBA-15吸附剂用于吸附CO₂，研究了TEPA浸渍方法、浸渍浓度、吸附温度和环境湿度对CO₂吸附性能的影响。此外，结合分子动力学（MD）和密度泛函理论（DFT）计算，探究了CO₂的扩散特性和吸附机理。研究发现，超声浸渍法制备的TEPA改性SBA-15吸附剂对CO₂的吸附性能高于搅拌浸渍法制备的吸附剂，这是由于超声浸渍可以提高TEPA在SBA-15孔道内分散的均匀性。随着TEPA超声浸渍浓度的增加，改性SBA-15吸附剂对CO₂吸附性能增强。在30℃时，SBA-15-2具有最高的CO₂吸附性能，为1.17 mmol/g。这是由于TEPA浸渍引入的含氮官能团对CO₂具有良好的亲和力。当温度从30℃上升到70℃时，改性SBA-15吸附剂的CO₂吸附性能均降低，这是因为CO₂吸附为放热反应。相比于搅拌浸渍法，超声浸渍法制备的SBA-15-2表现出更好的抗水性。这是由于TEPA超声浸渍过程引入的有机碳链在SBA-15孔道内具有更高的分散性，有机碳链通过降低SBA-15表面的羟基含量提高了其抗水性。在微观层面，MD模拟表明，在SBA-15内部浸渍TEPA可增加CO₂的有效吸附层厚度。此外，DFT模拟显示TEPA改性提高了SBA-15对CO₂的吸附能。本文可为胺改性介孔硅吸附剂在CO₂捕集应用方面提供参考。

该论文第一作者王佳欣博士是常州大学低碳清洁能源与安全高效燃烧课题组讲师，常州大学是第一作者和通讯作者单位。

英文摘要：

Amine-modified mesoporous silicon was widely used for CO₂ capture. However, its adsorption capability was significantly affected by temperature and humidity. In this paper, tetraethylenepentamine (TEPA) modified SBA-15 adsorbents were prepared for capturing CO₂. The effects of the modification method, the concentration of TEPA, the adsorption temperature, and the humidity of atmosphere on CO₂ adsorption capability were studied. Moreover, combined with molecular dynamics (MD) and density functional theory (DFT) computations, the diffusion characteristics and adsorption mechanism were explored. The CO₂ adsorption capability of the adsorbent prepared by the ultrasonic impregnation method was higher than those prepared by the stirring impregnation method, owing to that ultrasonic impregnation could promote the uniformity of TEPA. With the increase of TEPA concentration of SBA-15, the CO₂ adsorption capability increased. SBA-15-2 had the highest CO₂ adsorption capability of 1.17 mmol/g at 30 °C. This was due to the N-containing functional groups, showing good affinity for CO₂, introduced by TEPA impregnation. When the temperature increased from 30 °C to 70 °C, the CO₂ adsorption capability of all modified SBA-15 adsorbents decreased, since the CO₂ adsorption was an exothermic reaction. SBA-15-2 showed better water vapor resistance than SBA-15-2 (Stir). This was related to the higher dispersity of organic carbon chain introduced by TEPA modification after ultrasonic impregnation. The organic carbon chain of SBA-15-2 increased the water vapor resistance by reducing the hydroxyl group. Finally, from a microscopic aspect, the MD simulation suggested that impregnated TEPA inside SBA-15 may improve CO₂ capture by increasing the thickness of effective adsorption layer. Besides, the DFT simulation showed that TEPA modification increased the adsorption energy of SBA-15 on CO₂. This serves as a reference for later mesoporous silicon adsorbent research and development on CO₂ capture.

图解摘要：

原文链接：https://doi.org/10.1016/j.joei.2024.101555

                                                                   （撰稿：王佳欣     审核：朱宝忠）