Sequential Pore Functionalization in MOFs for Enhanced Carbon Dioxide Capture.

The capture of carbon dioxide (CO) is crucial for reducing greenhouse emissions and achieving net-zero emission goals. Metal-organic frameworks (MOFs) present a promising solution for carbon capture due to their structural adaptability, tunability, porosity, and pore modification. In this research, we explored the use of a copper (Cu(II))-based MOF called . After activation, generates one-dimensional channels with square cross sections, featuring sets of four Cu(II) open metal sites spaced by 6.042 Å, allowing strong interactions with coordinating molecules. To investigate this capability, was exposed to ammonia (NH) gas, resulting in hysteretic NH isotherms indicative of strong interactions between Cu(II) and NH. At 150 mbar and 298 K, the NH-loaded (∼1 mmol/g) material exhibited a 106% increase in CO uptake compared to that of the pristine . Carbon-13 solid-state nuclear magnetic resonance spectra and density functional theory calculations confirmed that the sequential loading of NH followed by CO adsorption generated a copper-carbamic acid complex within the pores of . Our study highlights the effectiveness of sequential pore functionalization in MOFs as an attractive strategy for enhancing the interactions of MOFs with small molecules such as CO.