Abstract: To address the issues of high regeneration energy consumption and solvent degradation loss at elevated temperatures for conventional alkanolamine-based carbon capture processes, this study investigated the catalytic regeneration reaction pathways for CO₂ desorption via carbamate decomposition through theoretical calculations. The catalytic performance and structure-activity relationships of various metal-substituted ZSM-5 zeolites for CO₂ desorption were explored, leading to the development of metal-modified ZSM-5 catalysts that facilitate C—N bond cleavage in carbamate molecules and reduce the activation energy of CO₂ desorption. Among the 16 investigated metals, Fe substituted ZSM-5 zeolite exhibited superior electron acceptance capability and significantly reduced the activation energy required for C—N bond activation. The Fe substituted ZSM-5 catalyst displayed optimal catalytic performance and stability for CO₂ desorption, effectively reducing desorption energy consumption and showing substantial potential for application in low-energy CO₂ capture technologies. Fe atoms in ZSM-5 utilize their d-orbitals to accept electrons from carbamate species, inducing electron density transfer from the C atom into the antibonding orbitals of N, resulting in C—N bond elongation and facilitating C—N bond cleavage.

Key words: ZSM-5 zeolite, desorption enhancement, carbon dioxide capture, first-principles calculations