Stabilization of Amine-Containing CO2 Adsorbents: Dramatic Effect of Water Vapor

摘要

Incorporation of organic amines onto large surface area porousnsolids via impregnation, postsynthesis grafting, or direct co-ncondensation as a promising approach for CO2 capture has gainednprominence in recent years.n1–13nWhen properly designed, suchnmaterials exhibit high adsorption capacity, fast CO2 adsorption andndesorption, and low energy requirement for recycling. However,ndespite the large number of contributions devoted to CO2 adsorptionnover amine-containing materials,n14nand despite the utmost impor-ntance of the long-term stability of such materials, no studiesnaddressed this issue through extensive recycling. The lifetime ofnadsorbents, which determines the frequency of their replacement,nis a critical property of equal importance as CO2 adsorption capacity,nselectivity, and kinetics with direct impact on the economics ofnany commercial scale operation. Here we show that, under dry CO2nadsorption desorption cycling, amine-containing materials ulti-nmately deactivate even under very mild conditions. We also identifynthe culprit and provide a method to dramatically enhance thenstability of such materials. Furthermore, we demonstrate thatndeactivated materials may be fully regenerated. The current findingsnprovide a straightforward strategy to using amine-containing CO2nadsorbents under conditions of unprecedented stability.