Phys.org February 9, 2023
Although numerous investigations have studied the formation of H2CO3 in water from CO2, the conversion of CO2 to H2CO3 in nanopores, and how it differs from that in bulk water, has not been understood. Researchers at Sandia National Laboratory used ReaxFF metadynamics molecular simulations to demonstrate striking differences in the free energy of CO2 conversion to H2CO3 in bulk and nanoconfined aqueous environments. They found that nanoconfinement not only reduces the energy barrier but also reverses the reaction from endothermic in bulk water to exothermic in nanoconfined water. Charged intermediates are observed more often under nanoconfinement than in bulk water. Stronger solvation and more favorable proton transfer with increasing nanoconfinement enhanced the thermodynamics and kinetics of the reaction. According to the researchers their work provides a detailed mechanistic understanding of an important step in the carbonation process, which depends intricately on confinement, surface chemistry, and CO2 concentration… read more. TECHNICAL ARTICLEÂ
Graphical abstract. Credit: J. Phys. Chem. Lett. 2023, 14, XXX, 1693–1701, February 9, 2023Â