Theory-based design principles for unprecedentedly high two-level CO2 utilization of CO2-derived metal-organic frameworks

Abstract

In this study, we theoretically developed a novel strategy for “two-level” CO2 utilization: the first level is “CO2 content” by directly converting CO2 into metal-organic frameworks (MOFs), and the second level is “CO2 capacity” by storing CO2 gas into their cavity. Despite its conceptual simplicity, experimental realization is rare due to technical difficulties and a lack of design principles for simultaneously maximizing CO2 content and CO2 capacity, leaving many unexplored possibilities. In this study, we designed over 1,500 hypothetical MOFs across 15 types of metal nodes combined with 14 types of newly designed CO2-derived ligands in over 40 topologies. We found that [-CO2NHNHCO2-] ligand assembled with [V2(CO2)4] node on the zeolite-like usf topology can have a large CO2 content of 50 wt%, which exceeds 31.6 wt% for the synthesized CO2-derived MOF. Grand Canonical Monte Carlo Simulation showed that the well-alignment of the paddlewheel in usf topology allows CO2 to be fully exposed to the cavity space, achieving high CO2 adsorption capacity. In addition, the fluorination of the ligand of MOFs significantly increases CO2 capacity and reaches unprecedented high CO2 utilization of up to 62 wt%. The design principles and database from this work provide opportunities and challenges for experimentalists in synthesizing new MOFs with breakthrough CO2 utilization.