In-situ synthesis of Fe-MOR molecular sieve catalyst for energy-efficient CO2 capture

Abstract

Techniques for capturing CO₂ based on traditional amine-based approaches face technical barriers of kinetic limitations and high energy requirements for solvent regeneration. Metal-molecular sieve composites are promising solid acid catalysts (SACs). In this paper, we report a one-step synthesis and preparation of Fe-MOR catalysts by introducing iron into the framework of mullite (MOR) zeolite molecular sieves via a simple and facile in-situ synthesis method, overcoming the uncontrolled metal distribution and instability generated by the production of such SAC catalyst via conventional methods such as loading or ion exchange and further enhancing their pore structure regulation and acidic structure. The catalysts were also applied to the catalytic desorption of CO₂ from a 30wt % MEA aqueous solution, and the CO₂ desorption rate and desorption capacity were increased by 46 % and 5 %, respectively, and the relative regeneration heat load was reduced by 17.4 % compared with the non-catalytic system when the molar ratio of Fe to Si was 2 %. In addition, the mechanism of Fe-MOR to improve the CO₂ capture performance was also discussed, and Fe doping helped increase both the activity of the acidic sites and the number of acidic sites.