Use of one-pot wet gel or precursor preparation and supercritical drying procedure for development of a high-performance CO2 sorbent

Abstract

The objective of this research was to develop a new high-performance CO₂ sorbent with a simple method. A new CO₂ aerogel sorbent was synthesized by using one-pot wet gel or sorbent precursor preparation, and supercritical drying (SCD). The performance of the aerogel sorbent prepared with SCD, A-SCD, is much better than that prepared with ambient pressure drying (APD). The highest CO₂ sorption capacity achieved with the new sorbent in 1% CO₂ flow stream within 20 min is 4.51 mmol g⁻¹, much higher than its state-of-art counterparts even with a 10% CO₂ gas mixture which is favorable to increase in CO₂ sorption capacity of any given sorbent. According to XPS data, the theoretical equilibrium CO₂ sorption capacity of the A-SCD is 7.99 mmol g⁻¹. The characterization results of N₂ adsorption/desorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and zeta potential measurements used for the first time in CO₂ research demonstrate that the pore structure and surface N concentration of the sorbent are significantly improved because of the use of SCD. The sorbent preparation method is inspiring and its resulting sorbent is exceptional in capacity and regenerability.