Co–Cu Bimetallic–Modified ATP Catalysts for Efficient and Low-Energy CO2 Capture

Abstract

The high energy consumption during regeneration of CO₂-rich amine solutions remains a major challenge for amine-based carbon capture. However, the addition of solid–acid catalyst accelerates the slow CO₂ desorption process while reducing the energy consumption for regeneration of the amine-rich solution. Herein, we developed Co and Cu bimetallic–modified attapulgite (ATP) solid–acid catalysts via impregnation to enable energy-efficient CO₂ desorption. The optimized Co₂–Cu₁/ATP catalyst exhibited exceptional performance in regenerating CO₂-rich monoethanolamine (MEA) solution (5 M) at 90°C, achieving a 171% increase in CO₂ desorption rate, a 287% enhancement in CO₂ desorption amount, and a 75.6% reduction in regeneration heat duty compared to non-catalytic processes. Comprehensive characterization (x-ray diffraction [XRD], Fourier transform infrared [FT-IR], NH₃-TPD, N₂ adsorption–desorption, scanning electron microscopy [SEM]/EDS, x-ray photoelectron spectroscopy [XPS]) revealed that the synergy between Co₃O₄ and CuO nanoparticles on ATP generated abundant strong acid sites and optimized mesoporous structure, facilitating proton transfer and carbamate decomposition. FT-IR analysis confirmed the catalytic accelerating effect of catalysts on the conversion of intermediates. The catalyst maintained 83% activity after eight regeneration cycles due to robust Co–O–Si/Cu–O–Si metal-support interactions. This work provides a cost-effective strategy for low-energy carbon capture, advancing industrial deployment of carbon capture, utilization, and storage (CCUS) technology.