Direct Air Capture of Carbon Dioxide into MFI Frameworks by Low-Temperature Swing Under Realistic Humidity.

The urgent need to combat global warming inspired the introduction of the concept of carbon dioxide direct air capture (CO2-DAC), a key strategy for decentralized greenhouse gas removal from air. In this study, a simple approach for CO2-DAC is introduced, utilizing ZSM-5 and its ion-exchanged analogues to effectively concentrate CO2 from humid air (80% RH) at 5 °C and enable its recovery at a moderate desorption temperature of 25 °C where in both cases, ambient air served as a sustainable CO2 source and desorption medium. Repeated adsorption (5 °C) and desorption (25 °C) cycles confirm the adsorbent stability under realistic conditions. Based on Monte Carlo (MC) and molecular dynamics (MD) simulations, a preferential CO2 adsorption via electrostatic interactions with minimal competitive adsorption with H2O is observed, explained by the facile diffusion of CO2 into the micropores compared to the preferred H2O adsorption on the outer surface of the zeolite. These experimental and theoretical insights pave the way for industrial CO2-DAC applications using zeolite-based adsorbents.