(600d) CO2 Capture and Transport Behavior in MIL-101(Cr)-Amine Bearing Polymer Sorbents Under Unconventional Direct Air Capture Conditions

Significant effort has been placed on developing materials for CO₂ capture from ambient air (direct air capture, DAC) to achieve negative emissions. Although a number of CO₂ capture sorbents have been developed for DAC application, sorbent materials have been investigated under a limited array of conditions that cannot cover the wide array of climates around the globe. Thus, to cover an array of deployment locations for DAC technologies, the CO₂ capture behavior of sorbent materials must be investigated over a wide range of temperatures and relative humidities. In this study, amine (TEPA, tetraethylenepentamine or PEI, poly(ethyleneimine)) functionalized MIL-101(Cr) metal-organic frameworks (MOFs) are prepared and their CO₂ adsorption behavior is investigated, including their equilibrium CO₂ capture capacities, CO₂ capture kinetics, as well competitive adsorption of CO₂ and moisture. The long-term stability of the hybrid sorbents is determined via repetitive CO₂ adsorption and regeneration cycles where the temperature and humidity conditions are controlled.