Heterometallic In(III)–Pd(II) Porous Metal–Organic Framework with Square-Octahedron Topology Displaying High CO₂ Uptake and Selectivity toward CH₄ and N₂

Abstract

The targeted synthesis of metal-organic frameworks (MOFs) with open metal sites, following reticular chemistry rules, provides a straightforward methodology toward the development of advanced porous materials especially for gas storage/separation applications. Using a palladated tetracarboxylate metalloligand as a 4-connected node, we succeeded in synthesizing the first heterobimetallic In(III)/Pd(II)-based MOF with square-octahedron (soc) topology. The new MOF, formulated as [InO(L)(HO)Cl]·n(solv) (1), features the oxo-centered trinuclear clusters, [In(μ-O)(-COO)], acting as trigonal-prismatic 6-connected nodes that linked together with the metalloligand trans-[PdCl(PDC)] (L) (PDC: pyridine-3,5-dicarboxylate) to form a 3D network. After successful activation of 1 using supercritical CO, high-resolution microporous analysis revealed the presence of small micropores (5.8 Å) with BET area of 795 m g and total pore volume of 0.35 cm g. The activated solid shows high gravimetric (92.3 cm g) and volumetric (120.9 cm cm) CO uptake at 273 K and 1 bar as well as high CO/CH (15.4 for a 50:50 molar mixture) and CO/N (131.7 for a 10:90 molar mixture) selectivity, with moderate Q for CO (29.8 kJ mol). Slight modifications of the synthesis conditions led to the formation of a different MOF with an anionic framework, having a chemical formula [MeNH][In(L)]· n(solv) (2). This MOF is constructed from pseudotetrahedral, mononuclear [In(-COO)] nodes bridged by four L linkers, resulting in a 3D network with PtS topology.

MOF‐Mediated Synthesis of Supported Fe‐Doped Pd Nanoparticles under Mild Conditions for Magnetically Recoverable Catalysis**

“…Figure 1 represents the MOF in which the [Fe 3 (μ 3 ‐O)] building blocks are connected with six different tetra‐carboxylate ligands to form a 3D structure with soc topology, isoreticular to an In analogue recently reported by Steriotis, Trikalitis and co‐workers [22] . This solvent‐free methodology, uncommon for the preparation of MOFs, has been adapted from previously reported methods [23] and allows the formation of the Fe analogue, which resulted as unfruitful using the conventional synthetic route for the PdIn‐MOF analogue, [22] yielding instead an Fe‐2D network with no Pd in the structure [24] . The porous nature of PdFe‐MOF, as established by N 2 sorption, reveals a total N 2 uptake of 250 cm 3 g −1 at 77 K and 0.8 bar with a calculated BET surface area of 830 m 2 g −1 for the activated material, which is consistent with those found in the isoreticular PdIn‐MOF.…”

MOF-Mediated Synthesis of Supported Fe-doped Pd Nanoparticles under Mild Conditions for Magnetically Recoverable Catalysis

“…This low value mostly corresponds to binding nitrate (ONOO -), as seen in the literature. [22] PdFe-NP-thermal and g) Pd@C (commercial). Figure S22 shows the Raman spectroscopy of three samples corresponding to PdFe-NP, PdFe-NP-300-6, and PdFe-NP-300-48.…”

“…[21] Herein, we present the formation of a composite material based on recently reported by Steriotis, Trikalitis and co-workers. [22] This solvent-free methodology, uncommon for the preparation of MOFs, has been adapted from previously reported methods [23] and allows the formation of the Fe analogue, which resulted as unfruitful using the conventional synthetic route for the PdIn-MOF analogue [22] yielding instead an Fe-2D network with no Pd in the structure. [24] The porous nature of PdFe-MOF, Preparation of the PdFe-NPs from PdFe-MOF has been achieved by adapting a previously reported procedure by Chaudret and co-workers, [7] based on the use of an amine (aniline) in the presence of H 2 (5 bar) at room temperature.…”

Cyclometalation of lanthanum(iii) based MOF for catalytic hydrogenation of carbon dioxide to formate

“…14 Recently, there has been a growing interest in the use of MOFs for conversion of CO 2 to useful chemicals. The majority of these studies have been focusing on water stable Zr-based MOFs, 12,[15][16][17][18][19][20][21] with the catalytically active centres introduced to the MOF backbone by post synthetic metalation of a bipyridine linker. Interestingly, none of these publications report on the activity of the parent MOF towards reduction of CO 2 but rather focus on the metals introduced into the pores of the MOF such as ruthenium, rhodium and iridium.…”