School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive, Atlanta, Georgia 30332, United States.
Global Thermostat LLC, 311 Ferst Drive, Atlanta, Georgia 30332, United States.
J Am Chem Soc. 2017 Mar 15;139(10):3627-3630. doi: 10.1021/jacs.7b00235. Epub 2017 Mar 3.
Studies on aminopolymer/oxide composite materials for direct CO capture from air have often focused on the prototypical poly(ethylenimine) (PEI) as the aminopolymer. However, it is known that PEI will oxidatively degrade at elevated temperatures. This degradation has been ascribed to the presence of secondary amines, which, when oxidized, lose their CO capture capacity. Here, we demonstrate the use of small molecule poly(propylenimine) (PPI) in linear and dendritic architectures supported in silica as adsorbent materials for direct CO capture from air. Regardless of amine loading or aminopolymer architecture, the PPI-based sorbents are found to be more efficient for CO capture than PEI-based sorbents. Moreover, PPI is found to be more resistant to oxidative degradation than PEI, even while containing secondary amines, as supported by FTIR, NMR, and ESI-MS studies. These results suggest that PPI-based CO sorbents may allow for longer sorbent working lifetimes due to an increased tolerance to sorbent regeneration conditions and suggest that the presence of secondary amines may not mean that all aminopolymers will oxidatively degrade.
用于从空气中直接捕获 CO 的氨基聚合物/氧化物复合材料的研究通常集中在典型的聚(亚乙基亚胺)(PEI)作为氨基聚合物上。然而,已知 PEI 在高温下会发生氧化降解。这种降解归因于仲胺的存在,当氧化时,它们会失去 CO 捕获能力。在这里,我们展示了小分子聚(丙稀亚胺)(PPI)在硅胶中作为吸附材料在直链和支化结构中的用途,用于从空气中直接捕获 CO。无论胺负载或氨基聚合物结构如何,基于 PPI 的吸附剂在 CO 捕获方面都比基于 PEI 的吸附剂更有效。此外,通过 FTIR、NMR 和 ESI-MS 研究发现,PPI 比 PEI 更能抵抗氧化降解,即使含有仲胺,这也得到了支持。这些结果表明,基于 PPI 的 CO 吸附剂可能由于对吸附剂再生条件的容忍度提高而允许更长的吸附剂工作寿命,并表明仲胺的存在并不意味着所有氨基聚合物都会发生氧化降解。