Solid-state NMR data for: Sequential pore functionalization in MOFs for enhanced carbon dioxide capture

The capture of carbon dioxide (CO2) 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
mCBMOF-1. After activation, mCBMOF-1 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, mCBMOF-1 was exposed to ammonia
(NH3) gas, resulting in hysteretic NH3 isotherms indicative of strong
interactions between Cu(II) and NH3. At 150 mbar and 298 K, the NH3-loaded
(∼1 mmol/g) material exhibited a 106% increase in CO2 uptake compared to
that of the pristine mCBMOF-1. Carbon-13 solid-state nuclear magnetic
resonance spectra and density functional theory calculations confirmed
that the sequential loading of NH3 followed by CO2 adsorption generated a
copper-carbamic acid complex within the pores of mCBMOF-1. 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 CO2.