Study on the desorption of CO2 from MEA aqueous solution over iron-titanium mixed oxide catalyst synthesized by microwave irradiation treatment

Wang, M. and Du, Y. and Zhang, H. and Lv, J. and Shi, H. and Lu, W. and Jin, J. and Xiong, Z. (2026) Study on the desorption of CO2 from MEA aqueous solution over iron-titanium mixed oxide catalyst synthesized by microwave irradiation treatment. Inorganic Chemistry Communications, 189 (P2): 116815.

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Abstract

The energy-intensive regeneration of amine-based solvents remains a major bottleneck in CO2 capture from fossil-fuel combustion flue, which is due to the high thermal consumption and slow desorption kinetics. To address these challenges, this study aims to develop a cost-effective, high-performance solid-acid catalyst to accelerate CO2 desorption from CO2-rich monoethanolamine (MEA) solutions while reducing energy input. A series of FeTiOz-M catalysts were synthesized via a microwave-assisting co-precipitation method and the as-prepared catalysts were characterized by XRD, FT-IR, Py-IR, XPS, NH3-TPD, and N₂ adsorption-desorption to elucidate structure-activity relationships. Results indicate that the Fe25Ti75Oz-M catalyst achieves a 36% increase in the average CO2 desorption rate and a 25.7% reduction in relative heat duty at 0.4 wt% loading and 90 °C, with certain stable activity maintained over five cycles. The enhanced performance is attributed to synergistic combination of abundant Brønsted and Lewis acid sites, activated surface hydroxyls by sulfate groups, and enlarged mesoporous surface area that facilitates carbamate diffusion. These findings demonstrate that rational design of bimetallic solid-acid catalysts can substantially improve CO2 desorption efficiency and energy savings, therefore providing a scalable and energy-efficient strategy for amine regeneration in industrial-level CO2 capture applications.