Catalytic CO2 desorption from amine solvent with framework incorporated Fe-ZSM−5 for energy-saving CO2 capture

Framework Fe-ZSM−5 was developed for catalytic CO 2 desorption from MEA. • Isolated tetrahedral Fe 3+ sites were incorporated into the MFI framework. • Framework Fe reduced Fe dissolution in MEA by more than 88% over 120 °C for 15 days. • Fe-ZSM−5 increased the average CO 2 desorption rate by 35% over the blank case under continuous operation. • Lewis acid-base pairs promote H 2 O-assisted carbamate decomposition. Catalytic CO 2 desorption from aqueous amine solvent is a promising strategy for energy-saving CO 2 capture from industrial flue gas. As an important candidate, conventional zeolite catalysts often suffer from insufficient activity, while metal incorporation can effectively regulate acidity but also causes metal-site dissolution. Herein, we prepared an excellent ZSM-5 zeolite with framework-incorporated Fe (Fe-ZSM−5) through feasible hydrothermal method. The coordination characterizations confirm that Fe-ZSM−5 contains isolated, tetrahedrally coordinated Fe 3 + within the MFI framework. Compared to impregnated Fe, the dissolution rate of framework Fe species in ethanolamine absorbent was reduced by more than 88%, which can effectively enhance catalytic performance and simultaneously avoid solvent degradation. Meanwhile, the incorporation of framework Fe modifies the acidic environment of the zeolite by generating Si-OH-Fe Brønsted acid sites and Fe-related Lewis acid sites. Fe-ZSM−5 exhibited high catalytic activity for CO 2 -rich MEA solution, with a peak desorption rate of 4.306 mmol·min −1 (48% higher than the blank case); the catalytic rate constants reach 2.0–2.4 × 10 −4 min −1 . This work proposes a novel design strategy for high-performance acid catalysts, representing a durable and efficient catalyst for reducing regeneration energy in amine-based CO 2 capture. Download: Download high-res image (299KB) Download: Download full-size image