Design of Ultra-Stable Solid Amine Adsorbents and Mechanisms of Hydroxyl Group-Dependent Deactivation for Reversible CO2 Capture from Flue Gas

作者：Meng Zhao, Liang Huang, Yanshan Gao, Ziling Wang, Shuyu Liang, Xuancan Zhu, Qiang Wang, Hong He, Dermot O’Hare · 发表于：Nano-Micro Letters · 年份：2025 · DOI：10.1007/s40820-025-01664-w · 被引用次数：32 · 研究领域：Carbon Dioxide Capture Technologies、Membrane Separation and Gas Transport、Covalent Organic Framework Applications

Abstract Although supported solid amine adsorbents have attracted great attention for CO 2 capture, critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO 2 capture. In this work, we reveal that the nature of surface hydroxyl groups (metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH) plays a key role in the deactivation mechanisms. The polyethyleneimine (PEI) supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO 2 capture step due to the breakage of amine-support hydrogen bonding networks, but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO 2 regeneration atmosphere. In contrast, PEI supported on Si–OH-containing substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH, but suffers from obvious urea formation during the pure CO 2 regeneration step. We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive. Based on the intrinsic understanding of degradation mechanisms, we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO 2 capacity of 2.45 mmol g −1 over 1000 adsorption–desorption cycles, together with negligible capacity ...