混合胺改性SBA-15的二氧化碳吸附特性

为实现廉价高效的二氧化碳捕集，新型燃烧后CO₂捕集固体吸附材料的设计和开发具有重要的研究意义。为提高CO₂吸附量，胺功能化改性吸附剂的方法主要有湿浸渍和表面嫁接。基于此，提出了“混合胺”修饰的概念，把湿浸渍和表面嫁接两种改性技术结合起来。把3-氨丙基三甲氧基硅烷（APTS）嫁接到分子筛SBA-15孔道表面，再把聚乙烯亚胺（PEI）浸渍到载体孔道的间隙，制备出高密度胺功能化的CO₂吸附剂。主要考察了不同含量的PEI和APTS功能化SBA-15的结构性能、CO₂吸附量及胺吸附效率。CO₂吸附结果表明，混合胺功能化SBA-15吸附主要依赖于动力学扩散。其中，SBA-15-（APTS-0.5-PEI-50），SBA-15-（APTS-1.0-PEI-50）和SBA-15-（APTS-2.0-PEI-30）在75℃时具有很好的吸附潜力。混合胺功能化SBA-15的胺吸附效率介于单纯嫁接和单纯浸渍的胺功能化SBA-15之间。

Mixed-amine functionalized SBA-15 for CO2 adsorption

To achieve an economical and effective approach of CO₂ capture, design of novel adsorbents for post-combustion CO₂ adsorption has important significance. To improve CO₂ adsorption capacity, two methods of wet impregnation and surface grafting have been used recently. "Mixed-amine" concept was proposed and these two methods were combined in this paper. 3-Aminopropyltrimethoxysilane (APTS) was first grafted onto the surface of SBA-15 and then polyethylenimine (PEI) was impregnated into the space of pores. This novel adsorbent possessed a very high density of amine groups. The structural property, CO₂ adsorption capacity and amine efficiency of mixed-amine functionalized SBA-15 with different ratios of APTS and PEI were investigated. The CO₂ adsorption result showed that the performance of mixed-amine functionalized SBA-15 depended on kinetic diffusion. SBA-15-(APTS-0.5-PEI-50), SBA-15-(APTS-1.0-PEI-50) and SBA-15-(APTS-2.0-PEI-30) could be identified as potential adsorbents at 75℃. The amine efficiency of mixed-amine functionalized SBA-15 was between purely impregnated and grafted ones.