Target-specific modification of diethylenetriamine with hydroxyalkyls: Efficient absorbents for CO₂ capture

Chemical absorption of CO₂ by amine solutions is an industrialized operation and currently represents the most practical technology worldwide. However, the development of amine absorbents with high efficiency and energy-saving benefits remains a major challenge. Here, we developed a novel class of amines through the target-specific modification of the secondary amine group in diethylenetriamine (DETA) with various hydroxyalkyls. The obtained amines present enhanced overall efficiency for CO₂ capture, especially with regards to the absorption/desorption rates and recyclability. Significantly, the regeneration energy consumption for the developed amines can be reduced to a remarkable low value of 2.78 GJ t^-1 CO₂. Moreover, the CO₂ absorption and desorption processes were closely monitored by nuclear magnetic resonance (NMR). Combined with density functional theory (DFT) calculations, the mechanism of the developed amine for CO₂ capture was fully elucidated. This targeted modification strategy provides a new avenue for the development of efficient amine absorbents for practical CO₂ capture.