Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA Email Address.
ChemSusChem. 2023 Mar 8;16(5):e202201908. doi: 10.1002/cssc.202201908. Epub 2023 Jan 9.
Amine-based adsorbents are promising for direct air capture of CO , yet oxidative degradation remains a key unmitigated risk hindering wide-scale deployment. Borrowing wisdom from the basic auto-oxidation scheme, insights are gained into the underlying degradation mechanisms of polyamines by quantum chemical, advanced sampling simulations, adsorbent synthesis, and accelerated degradation experiments. The reaction kinetics of polyamines are contrasted with that of typical aliphatic polymers and they elucidate for the first time the critical role of aminoalkyl hydroperoxide decomposition in the oxidative degradation of amino-oligomers. The experimentally observed variation in oxidative stability of polyamines with different backbone structures is explained by the relationship between the local chemical structure and the free energy barrier of aminoalkyl hydroperoxide decomposition, suggesting that its energetics can be used as a descriptor to screen and design new polyamines with improved stability. The developed computational capability sheds light on radical-induced degradation chemistry of other organic functional materials.
胺基吸附剂在直接从空气中捕获 CO 方面很有前景，但氧化降解仍然是一个关键的未缓解风险，阻碍了其广泛应用。通过借鉴基本的自动氧化方案，通过量子化学、高级采样模拟、吸附剂合成和加速降解实验，深入了解多胺的潜在降解机制。对比了多胺的反应动力学与典型脂肪族聚合物的反应动力学，并首次阐明了氨烷基过氧化物分解在氨寡聚物氧化降解中的关键作用。通过实验观察到不同骨架结构的多胺的氧化稳定性变化，这可以通过局部化学结构与氨烷基过氧化物分解的自由能势垒之间的关系来解释，这表明其能量学可以用作筛选和设计具有改进稳定性的新型多胺的描述符。所开发的计算能力揭示了其他有机功能材料的自由基诱导降解化学。
