In situ self-assembly of amine-rich carbon supraparticles for rapid CO2 capture

Abstract

The urgent demand for efficient CO₂ capture from high-temperature flue gas streams necessitates the development of advanced adsorbents with robust structural stability and rapid sorption kinetics. While amine-functionalized materials offer promising affinity for CO₂ within elevated-temperature operational windows, conventional post-loading strategies often compromise pore accessibility and hinder mass transfer due to network obstruction. Here, we introduce an innovative in situ self-assembly approach to incorporate amine functionalities directly into the interconnected meso- and macroporous framework of carbon supraparticles (CSs). This strategy takes advantage of hydroxyl-rich carbon nanofibers (CNFs) during in situ synthesis to help retain amines within the CS pores and anchor them more strongly to the support, leading to amines showing a more uniform distribution, and better resistance to evaporation and leaching. The resulting material demonstrates rapid CO₂ uptake at 1 bar and 70 °C, achieving an impressive adsorption rate of 0.17 mmol g⁻¹ min⁻¹ and a capacity of 2.87 mmol g⁻¹, while exhibiting appropriate adsorption stability over repeated adsorption–desorption cycles. These performance metrics represent 4-fold and 2.4-fold enhancements in rate and capacity, respectively, compared to conventional post-loading approaches. Overall, this work presents a scalable and sustainable strategy for developing high-efficiency CO₂ capture materials suited for industrial deployment.