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.