Photothermal effect coupled with proton transfer catalysis accelerating CO2 desorption in organic amines with Ru doped MnOOH

Abstract

Catalytic desorption can reduce the activation energy of the reaction and increase the desorption reaction rate, and is one of the most promising technologies to solve energy consumption problems of CO2 capture technology for organic amine solutions. In order to further reduce desorption energy consumption, we propose a new method of utilizing the photothermal effect of catalysts to increase desorption temperature and accelerate reaction kinetics, and coupling the proton transfer ability of the catalyst itself to form multifunctional catalysis. In this work, we synthesized RuxMn1-xOOH catalyst by introducing Ru atoms at the Mn vacancies on the MnOOH surface, grasping the advantages of the photothermal and proton transfer ability of Ru-dopants. The results showed that the CO2 desorption capacity increased by 43.1% with adding MnOOH compared to without a catalyst. The Ru-doped catalyst demonstrated a 54.7% increase in CO2 desorption efficiency, with an additional 98.2% surge attributed to the in-situ photothermal effect generated by the catalyst under light irradiation. Characterization and density functional theory (DFT) calculations revealed that Ru doping significantly enhanced the proton transfer ability while simultaneously weakens the adsorption capacity of monoethanolamine (MEA) on the catalyst surface. Moreover, the stronger photothermal effect introduced by Ru leads to an increase in the surface temperature of the catalyst, which is key to the faster and efficient desorption of CO2. This work provides a new approach to improve the proton transfer ability of catalysts and offers a novel photothermal coupled catalytic scheme for CO2 desorption in organic amine carbon capture technology.