An ethane-trapping MOF PCN-250 for highly selective adsorption of ethane over ethylene

A Zwitterionic Ligand‐Based Cationic Metal‐Organic Framework for Rapidly Selective Dye Capture and Highly Efficient Cr2O72− Removal

“…Metal-organic frameworks (MOFs), as porousc rystalline solids that consisto fm etal ions or metal-containing clusters connected by multidentate organic ligands, have received al ot of attention because of their unique characteristics, such as well-defined structures, fascinating properties, designability,a nd controllability on molecular scale. [1] Among various MOFs, copperpaddlewheel-based MOFs (CP-MOF)r epresent au nique subclass andh ave been widely studied. In 2005, Chen et al synthesized ac opper-tetracarboxylatef ramework (MOF-505) using 3,3',5,5'-biphenyltetracarboxylic acid, giving at hree-dimensional (3D) 4-connected nbo framework containing squarep lanar dicopper paddlewheel {Cu 2 (O 2 C) 4 }c lusters.…”

Alternatives to Cryogenic Distillation: Advanced Porous Materials in Adsorptive Light Olefin/Paraffin Separations

“…A high ethane uptake capacity of 6.93 mmol/g was observed in Ni(bdc)(ted) 0.5 at 273 K and 100 kPa, and the ideal ethane/ethylene adsorption selectivities predicted by IAST were in the range of 2–7.8 under the same condition for 10:90 ethane/ethylene mixture. Following the idea to obtain ethane‐selective MOF with excellent gas adsorption capacity, Chen et al evaluated the potential of PCN‐250 for ethane/ethylene separation . Built from trimers of iron octahedra and 3,3′,5,5′‐azobenzenetetracarboxylate, PCN‐250 (Fe) has a high specific BET surface area of 1470 m 2 g −1 , and can hold 5.21 and 4.22 mmol g −1 of ethane and ethylene, respectively, at 298 K and 100 kPa.…”

“…The preferential adsorption of ethane is reflected by a higher adsorption enthalpy of ethane and simulated by GCMC method. IAST calculation predicted that C 2 H 6 /C 2 H 4 adsorption selectivities in the MOF fall in the range of 1.9–4.0 at 298 K . Similarly, Chen et al reported another iron MOF MIL‐142A with ethane adsorption selectivity (5.8–1.5 in the pressure range of 0–100 kPa) based on the ligand combination of terephthalate and 1,3,5‐tris(4‐carboxyphenyl)benzene .…”

Moisture stability of ethane‐selective Ni(II), Fe(III), Zr(IV)‐based metal–organic frameworks

“…The mass loss of 32.1% for H 4 bptc is close to the theoretical value (32.4%) calculated from the formula Zr 6 O 4 (OH) 4 (bptc) 3 . Therefore, Zr‐bptc is thermally stable to 702 K. The thermal decomposition temperature of Zr‐bptc (702 K) outperformed most reported ethane‐selective MOFs, such as IRMOF‐8 (673 K), PCN‐250 (673 K), PCN‐245 (625 K), Ni(bdc)(ted) 0.5 (673 K), ZIF‐69 (643 K), and MIL‐142A (573 K), but slight lower than UiO‐66 (739 K) . The high thermal stability of Zr‐bptc and UiO‐66 probably lies on the strong Zr‐O coordination bonds and the 12‐connected Zr 6 (μ 3 ‐O) 4 (μ 3 ‐OH) 4 (COO) 12 SBU of Zr‐bptc and UiO‐66.…”

“…Walton's group reported that ethane‐selective UiO‐66 could maintain its framework intact after complete water vapor adsorption isotherm tests, and they attributed the good stability of UiO‐66 to its stable Zr inorganic clusters. Our group reported that ethane‐selective PCN‐250 exhibited good moisture stability after exposure to 90% RH for a month, and the excellent moisture stability of PCN‐250 was due to strong Fe‐O bonds in the framework.…”