Details

Autor(en) / Beteiligte

• Li, Sichi
• Cerón, Maira R.
• Eshelman, Hannah V.
• Varni, Anthony J.
• Maiti, Amitesh
• Akhade, Sneha
• Pang, Simon H.

Titel

Probing the Kinetic Origin of Varying Oxidative Stability of Ethyl‐ vs. Propyl‐spaced Amines for Direct Air Capture

Ist Teil von

• ChemSusChem, 2023-03, Vol.16 (5), p.e202201908-n/a

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Amine‐based adsorbents are promising for direct air capture of CO2, 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. Advanced simulations and accelerated degradation experiments are presented to elucidate the mechanism of oxidative degradation of amines for direct air capture. The rate‐determining nature of the alkyl hydroperoxide (ROOH) decomposition step and its structure‐dependent kinetics rationalize the varying oxidative stability across different amine‐containing adsorbents.