A stable dual-function lanthanum MOF: Simultaneous CO2 capture and catalysis

Abstract

Carbon dioxide (CO₂) capture has become a hot topic in recent years because of global warming issues. However, most research has focused primarily on gas capture, with limited methods available for achieving both CO₂ capture and conversion within a single material. Here, we synthesized FMU-101, a metal-organic framework (MOF) with metal-open sites, through the self-assembly of [1,1′-Biphenyl]-3,3′,5-tricarboxylic acid and lanthanide ions in a solvothermal environment. FMU-101 features hexagonal one-dimensional pores with a diameter of 1.4 nm. The presence of free dimethylamine cations and metal open sites in the channel contributes to its remarkable capability for selectively enriching CO₂ from CO₂/CH₄ mixtures in dynamic breakthrough experiments. Furthermore, the metal-open sites in FMU-101 play a crucial role in CO₂ fixation, serving as effective catalytic sites for converting the adsorbed CO₂ into high-value chloropropylene carbonate, a versatile chemical intermediate. The segregation and conversion mechanisms were further elucidated through density-functional theory (DFT) calculations and Grand Canonical Monte Carlo (GCMC) simulations, which highlighted the critical role of metal-open sites in CO₂ adsorption and transformation.