High-Nuclearity Ln210Al140 Clusters: Neonates of Open Hollow Dodecahedral Cage Families.

Open hollow dodecahedral cage clusters have long been a coveted target in synthetic chemistry, yet their creation poses immense challenges. Here we report two open hollow dodecahedral lanthanide-aluminum (Ln-Al) heterometallic cage clusters, namely, [Ln210Al140(µ2-OH)210(µ3-OH)540(OAc)180(H2O)156](ClO4)120·(MeCN)x·(H2O)y, (Ln = Dy and x = 27, y = 300 for 1; Ln = Y and x = 28, y = 420 for 2). Remarkably, the 350 metal atoms in 1 and 2 display a Keplerate-type four-shell structure of truncated icosidodecahedron@dodecahedron@dodecahedron@icosidodecahedron. The diameter of the cationic cluster in 1 is approximately 5.0 nm, with an inner cavity diameter of about 2.8 nm and a window diameter of roughly 0.66 nm. The cluster in 1 boasts an accessible inner void volume of up to 15,000 Å3. Notably, these cage clusters maintain stability in water, and the truncated icosidodecahedrons in 1 and 2 are the first of their kind synthesized to date. Given that the open hollow dodecahedral Ln-Al cage cluster has never been reported before, this work represents a member in the family of hollow open dodecahedral cages.

Enhancement of Magneto-Chiral Dichroism Intensity by Chemical Design: The Key Role of Magnetic-Dipole Allowed Transitions.

Here we report on the strong magneto-chiral dichroism (MChD) detected through visible and near-infrared light absorption up to 5.0 T on {Er5Ni6} metal clusters obtained by reaction of enantiopure chiral ligands and NiII and ErIII precursors. Single-crystal diffraction analysis reveals that these compounds are 3d-4f heterometallic clusters, showing helical chirality. MChD spectroscopy reveals a high gMChD dissymmetry factor of ca. 0.24 T-1 (T = 4.0 K, B = 1.0 T) for the 4I13/2 ← 4I15/2 magnetic-dipole allowed electronic transition of the ErIII centers. This record value is 1 or 2 orders of magnitude higher than that of the d-d electronic transitions of the NiII ions and the others f-f electric-dipole induced transitions of the ErIII centers. These findings clearly show the key role that magnetic-dipole allowed transitions have in the rational design of chiral lanthanide systems showing strong MChD.

LnIII/CuI Bimetallic Nanoclusters with Enhanced NIR-II Luminescence.

Coinage-metal clusters with excellent luminescence properties have attracted considerable interest due to their intriguing structures and potential applications. However, achieving strong near-infrared (NIR) luminescence in these clusters is highly challenging. Here, we have successfully synthesized the first LnIII/CuI bimetallic clusters, formulated as [LnCu54O6Cl3(2-MeO-PhC≡C)36] (ClO4)6 (Ln = Yb for YbCu54, Er for ErCu54, and Gd for GdCu54). Single crystal X-ray diffraction showed that the LnCu54 clusters have a three-layered core-shell structure, consisting of (LnO6)@Cu18Cl3@Cu36 units protected by 36 2-MeO-PhC≡C- ligands. Notably, the YbCu54 cluster exhibits significant NIR-II luminescence at 986 nm with the solid quantum efficiency of 33.3%, the highest among Cu clusters with NIR-II emission. This work not only reports the first category of LnIII/CuI clusters but also presents a method to enhance NIR luminescence in coinage-metal clusters through the incorporation of LnIII ions.

Strong NIR-II Magneto-Optical Activity of a Chiral Sm15Cu54 Cage.

The magneto-optical response of chiral materials holds significant potential for applications in physics, chemistry, and biology. However, exploration of the near-infrared (NIR) magneto-optical response remains limited. Herein, we report the synthesis and strong NIR-II magneto-optical activity of three pairs of chiral 3d-4f clusters of R/S-Ln15Cu54 (Ln = Sm, Gd, and Dy). Structural analysis reveals that R/S-Ln15Cu54 features a triangular prism cage with C3 symmetry. Interestingly, magnetic circular dichroism (MCD) spectra exhibit remarkable magneto-optical response in the NIR-II region, driven by the f-f transition. The maximum g-factor of R/S-Sm15Cu54 reaches 5.5 × 10-3 T-1 around 1300-1450 nm, surpassing values associated with DyIII and CuII ions. This remarkable NIR-II magneto-optical activity may be attributed to strong magnetic-dipole-allowed f-f transitions and helix chirality of the structure. This work not only presents the largest Ln-Cu clusters to date but also demonstrate the key role of magnetic-dipole-allowed transitions on magneto-optical activity.

Tuning Electrocatalytic Water Oxidation Activity: Insights from the Active-Site Distance in LnCu6 Clusters.

Atomically precise metal clusters serve as a unique model for unraveling the intricate mechanism of the catalytic reaction and exploring the complex relationship between structure and activity. Herein, three series of water-soluble heterometallic clusters LnCu6, abbreviated as LnCu6-AC (Ln = La, Nd, Gd, Er, Yb; HAC = acetic acid), LnCu6-IM (Ln = La and Nd; IM = Imidazole), and LnCu6-IDA (Ln = Nd; H2IDA = Iminodiacetic acid) are presented, each featuring a uniform metallic core stabilized by distinct protected ligands. Crystal structure analysis reveals a triangular prism topology formed by six Cu2+ ions around one Ln3+ ion in LnCu6, with variations in Cu···Cu distances attributed to different ligands. Electrocatalytic oxygen evolution reaction (OER) shows that these different LnCu6 clusters exhibit different OER activities with remarkable turnover frequency of 135 s-1 for NdCu6-AC, 79 s-1 for NdCu6-IM and 32 s-1 for NdCu6-IDA. Structural analysis and Density Functional Theory (DFT) calculations underscore the correlation between shorter Cu···Cu distances and improves OER catalytic activity, emphasizing the pivotal role of active-site distance in regulating electrocatalytic OER activities. These results provide valuable insights into the OER mechanism and contribute to the design of efficient homogeneous OER electrocatalysts.

An Unusual Crystalline Porous Framework Constructed from Multitypes of Cages with Proton Conduction Property and Heterogeneous Catalytic Activity for Pyrazole Synthesis.

An unusual crystalline porous framework constructed from four types of cages, including all-inorganic Keggin-type polyoxometalate (POM) cages [H3W12O40]5-, organic hexamethylenetetramine (Hmt) cages, nanosized silver-Hmt coordination cages, and giant POM-silver-Hmt cages, was hydrothermally synthesized and structurally characterized. The framework features a highly symmetrical structure with one-dimensional nanoscale channels and holds good thermal/solvent stability, which endow it with proton conduction properties and heterogeneous catalytic activity for pyrazole. This paper not only contributes to broadening the structural diversity of cage-based crystalline porous framework materials but also sheds new light on the design of new functional framework materials.

Magneto-optical Properties of Chiral Co2Ln and Co3Ln2 (Ln = Dy and Er) Clusters.

A series of chiral heterometallic Ln-Co clusters, denoted as Co2Ln and Co3Ln2 (Ln = Dy and Er), were synthesized by reacting the chiral chelating ligand (R/S)-2-(1-hydroxyethyl)pyridine (Hmpm), CoAc2·4H2O, and Ln(NO3)3·6H2O. Co2Ln and Co3Ln2 exhibit perfect mirror images in circular dichroism within the 320-700 nm range. Notably, the Co2Er and Co3Er2 clusters display pronounced magnetic circular dichroism (MCD) responses of the hypersensitive f-f transitions 4I15/2-4G11/2 at 375 nm and 4I15/2-2H11/2 at 520 nm of ErIII ions. This study highlights the strong magneto-optical activity associated with hypersensitive f-f transitions in chiral 3d-4f magnetic clusters.

An Ultra-stable Supramolecular Framework Based on Consecutive Side-by-side Hydrogen Bonds for One-step C2H4/C2H6 Separation.

The one-step efficient separation of high-purity C2H4 from C2H4/C2H6 mixtures by hydrogen-bonded organic frameworks (HOFs) faces two problems: lack of strategies for constructing stable pores in HOFs and how to obtain high C2H6 selectivity. Herein, we have developed a microporous Mortise-Tenon-type HOF (MTHOF-1, MT is short for Mortise-Tenon structure) with a new self-assembly mode for C2H4/C2H6 separation. Unlike previous HOFs which usually possess discrete head-to-head hydrogen bonds, MTHOF-1 is assembled by unique consecutive side-by-side hydrogen bonds, which result in mortise-and-tenon pores decorated with orderly arranged amide groups and benzene rings. As expected, MTHOF-1 exhibits excellent stability under various conditions and shows clear separation trends for C2H6/C2H4. The IAST selectivity is as high as 2.15 at 298 K. More importantly, dynamic breakthrough experiments have demonstrated that MTHOF-1 can effectively separate the C2H6/C2H4 feed gas to obtain polymer-grade C2H4 in one step even under high-humidity conditions.

From Helices to Crystals: Multiscale Representation of Chirality in Double-Helix Structures.

Single crystals with chiral shapes aroused the interest of chemists due to their fascinating polarization rotation properties. Although the formation of large-scale spiral structures is considered to be a potential factor in chiral crystals, the precise mechanism behind their formation remains elusive. Herein, we present a rare phenomenon involving the multitransfer and expression of chirality at micro-, meso-, and macroscopic levels, starting from chiral carbon atoms and extending to the double-helical secondary structure, ultimately resulting in the chiral geometry of crystals. The assembly of the chiral double helices is facilitated by the dual characteristics of amide groups derived from amino acids, which serve as both hydrogen bond donors and receptors, similar to the assembly pattern observed in DNA. Crystal face analysis and theoretical morphology reveal two critical factors for the mechanism of the chiral crystal: inherent intrinsically symmetrical distribution of crystal faces and their acquired growth. Importantly, the magnetic circular dichroism (MCD) study reveals the strong magneto-optical response of the hypersensitive f-f transition in the UV-vis-NIR region, which is much stronger than previously observed signals. Remarkably, an external magnetic field can reverse the CD signal. This research highlights the potential of lanthanide-based chiral helical structures as promising magneto-optical materials.

Conductive Lanthanide Metal-Organic Frameworks with Exceptionally High Stability.

Electrically conductive metal-organic frameworks (MOFs) have been extensively studied for their potential uses in energy-related technologies and sensors. However, achieving that goal requires MOFs to be highly stable and maintain their conductivity under practical operating conditions with varying solution environments and temperatures. Herein, we have designed and synthesized a new series of {[Ln4(µ4-O)(µ3-OH)3(INA)3(GA)3](CF3SO3)(H2O)6}n (denoted as Ln4-MOFs, Ln = Gd, Tm, and Lu, INA = isonicotinic acid, GA = glycolic acid) single crystals, where electrons are found to transport along the π-π stacked aromatic carbon rings in the crystals. The Ln4-MOFs show remarkable stability, with minimal changes in conductivity under varying solution pH (1-12), temperature (373 K), and electric field as high as 800 000 V/m. This stability is achieved through the formation of strong coordination bonds between high-valent Ln(III) ions and rigid carboxylic linkers as well as hydrogen bonds that enhance the robustness of the electron transport path. The demonstrated lanthanide MOFs pave the way for the design of stable and conductive MOFs.

Exploration and Insights on Topology Adjustment of Giant Heterometallic Cages Featuring Inorganic Skeletons Assisted by Machine Learning.

Inorganic molecular cages are emerging multifunctional molecular-based platforms with the unique merits of rigid skeletons and inherited properties from constituent metal ions. However, the sensitive coordination bonds and vast synthetic space have limited their systematic exploration. Herein, two giant cage-like clusters featuring the organic ligand-directed inorganic skeletons of Ni4[La74Ni104(IDA)96(OH)184(C2O4)12(H2O)76]·(NO3)38·(H2O)120 (La74Ni104, 5 × 5 × 3 - C2O4) and [La84Ni132(IDA)108(OH)168(C2O4)24(NO3)12(H2O)116]·(NO3)72·(H2O)296 (La84Ni132, 5 × 5 × 5 - C2O4) were discovered by a high-throughput synthetic search. With the assistance of machine learning analysis of the experimental data, phase diagrams of the two clusters in a four-parameter synthetic space were depicted. The effect of alkali, oxalate, and other parameters on the formation of clusters and the mechanism regulating the size of two n × m × l clusters were elucidated. This work uses high-throughput synthesis and machine learning methods to improve the efficiency of 3d-4f cluster discovery and finds the highest-nuclearity 3d-4f cluster to date by regulating the size of the n × m × l inorganic cages through oxalate ions, which pushes the synthetic methodology study on elusive inorganic giant cages in a significantly systematic way.

Functionalization of Keggin Fe13-Oxo Clusters.

Two Keggin Fe13-oxo clusters, [Pr12Fe33(NO3)6(L-van)4(D-van)5(TEOA)12(µ3-OH)12(µ4-OH)12(µ4-O)28(H2O)4]·(ClO4)3·(NO3)·10H2O (1) and [Dy12Fe33(NO3)2(L-van)3(D-van)3(TEOA)12(µ3-OH)18(µ4-OH)6(µ4-O)28(H2O)9]·(ClO4)5·(NO3)6·15H2O (2), where L-van = l-valine, D-van = d-valine, and TEOA = triethanolamine, were prepared by using Ln3+ as a stabilizer. Cluster 1 crystallizes in a chiral space group of C2, while cluster 2 crystallizes in a centrosymmetric space group of Pnma. Dynamic magnetic measurements of 2 under a zero direct-current field reveal that 2 exhibits single-molecule-magnet characteristics with an energy barrier of 18.79 K. Significantly, the formation of the chiral cluster 1 is closely related to the larger radius of the Pr3+ ion.

Uranyl Polyoxotungstate Cluster for Visible-Light-Driven Heterogeneous C-H Selective Fluorination.

The selective fluorination of C-H bonds at room temperature using heterogeneous visible-light catalysts is both interesting and challenging. Herein, we present the heterogeneous sandwich-type structure uranyl-polyoxotungstate cluster Na17{Na@[(SbW9O33)2(UO2)6(PO3OH)6]}·46H2O (denoted as U6P6) to regulate the selective fluorination of the C-H bond under visible light and room temperature. This is the first report in which uranyl participates in the fluorination reaction in the form of an insoluble substance. U6P6 is capable of the effective selective fluorination of cycloalkanes and the recyclability of the photocatalyst due to the synergistic effect of multiple uranyl (UO2)2+ and the insolubility of organic reagents of polyoxotungstate. In situ electron paramagnetic resonance spectroscopy captured the generation of cycloalkane radicals during the photoreaction, confirming the mechanism of direct hydrogen atom transfer.

Counterintuitive Lanthanide Hydrolysis-Induced Assembly Mechanism.

The understanding of the hydrolysis mechanism of lanthanide ions is limited by their elusive coordination configuration and undeveloped technology. A potential solution by high-resolution mass spectroscopy studies is hindered by the lack of a stable model under electrospray ionization (ESI) conditions and the complexity of the spectra. Herein, it is demonstrated that diketonate ligands can efficiently stabilize the hydrolyzed intermediate cluster of Ln3+ under ESI conditions, and an effective mass difference fingerprint of isomorphism (MDFI) method is proposed, which can allow the determination of the nuclearity-number of the species without depth resolution. Thus, the hydrolysis of Ln3+ into an atomically precise hydroxide cluster is observed at the level of precise formulae. The species evolution upon hydrolysis is along the dominant path of {Eu3}-{Eu4}-{Eu9}-{Eu10}-{Eu11}-{Eu15}-{Eu16} and a nondominant path of {Eu3}-{Eu4}-{Eu8-1}-{Eu8-2} under the investigated conditions. The crystal of the {Eu16} species was obtained via low-temperature crystallization, and single-crystal X-ray diffraction studies show that its structure contains three octahedral {o-Ln6} units. The contradiction between multiple {o-Ln6} units in the structure and the absence in the formation process indicates that the repetitive subunit observed in the structure does not necessarily correspond to the construction units of high-nuclearity clusters. Photophysical measurements indicate that Eu16 cluster has a high total emission quantum efficacy of 12.8% in the solid state. This study provides fundamental insights into the formation, evolution, and assembly of small lanthanide hydroxide units upon hydrolysis, which is vital for the goal of directional synthesis of lanthanide hydroxide clusters.

Magnetic 3d-4f Chiral Clusters Showing Multimetal Site Magneto-Chiral Dichroism.

Here, we report the molecular self-assembly of hydroxido-bridged {Ln5Ni6} ((Ln3+ = Dy3+, Y3+) metal clusters by the reaction of enantiopure chiral ligands, namely, (R/S)-(2-hydroxy-3-methoxybenzyl)-serine), with NiII and LnIII precursors. Single-crystal diffraction analysis reveals that these compounds are isostructural sandwich-like 3d-4f heterometallic clusters showing helical chirality. Direct current magnetic measurements on {Dy5Ni6} indicates ferromagnetic coupling between DyIII and NiII centers, whereas those on {Y5Ni6} denote that the NiII centers are antiferromagnetically coupled and/or magnetically anisotropic. Magneto-chiral dichroism (MChD) measurements on {Dy5Ni6} and its comparison to that of {Y5Ni6} provide the first experimental observation of intense multimetal site MChD signals in the visible-near-infrared region. Moreover, the comparison of MChD with natural and magnetic circular dichroism spectra unambiguously demonstrate for the first time that the MChD signals associated with the NiII d-d transitions are mostly driven by natural optical activity and those associated with the DyIII f-f transitions are driven by magnetic optical activity.

Aminopolyol-Dependent Assembly of Heterometallic Lanthanide-Iron-Oxo Clusters.

Lanthanide-iron clusters usually display interesting structures and outstanding magnetic properties. However, due to the high reactivity (acidity) of the Fe3+-H2O bond and the inability to form a terminal oxo ligand, the preparation of high-nuclearity Ln-Fe clusters is a great challenge. Herein, a series of lanthanide-iron-oxo clusters with the formulas [Y6Fe(HL)10(NO3)2(EG)2(µ3-OH)8(H2O)4]·ClO4·N-H2BDEA·2H2O (Y6Fe, 1, H2L = 3-hydroxypivalic acid, EG = ethylene glycol, N-H2BDEA = 2,2'-(butylimino)diethanol), [Ln8Fe3(H2TEOA)2(HTEOA)2(HL)10(µ3-OH)9(µ2-OH)(µ4-O)2(H2O)4]·(NO3)3·xH2O (Ln = Y, x = 13 for 2, Y8Fe3; Ln = Dy, x = 10 for 3, Dy8Fe3; H3TEOA = triethanolamine), and [Ln12Fe14(HL)16(µ3-OH)20(µ2-OH)12(µ4-O)12(H2O)12]·(NO3)6·xH2O (Ln = Y, x = 40 for 4, Y12Fe14; Ln = Dy, x = 30 for 5, Dy12Fe14) were obtained by adjusting the pH with different aminopolyols as organic alkalis. Structural analysis showed that a cubane-like unit was the main structural unit in compounds 1-5. Compound 1 was formed by two {Y3Fe(µ3-OH)4} units with the common vertices, and compounds 2 and 3 were formed by two {Y3Fe(µ3-OH)3(µ4-O)} units with the common vertices bridging a quadrilateral unit {Ln2Fe2(µ3-OH)3(µ2-OH)}. The basic structural units of cubane-like {Ln2Fe2(µ3-OH)(µ4-O)3}, triangular {LnFe2(µ3-OH)2(µ4-O)}, and neutral iron-hydroxyl {Fe(µ3-OH)(µ2-OH)2} were found in compounds 4 and 5. The universality of building blocks for the assembly has been demonstrated in high-nuclearity lanthanide-iron-oxo clusters. Meanwhile, the structural regulation of the lanthanide-iron-oxo clusters 1-5 was realized by adjusting the pH with different organic alkalis, which provided the reference for the effective synthesis of high-nuclearity lanthanide-iron-oxo clusters. Magnetic studies showed that 3 and 5 displayed a slow magnetic relaxation behavior.

Photoluminescence of Lanthanide-Titanium-Oxo Clusters Eu9Ti2 and Tb9Ti2 Based on a ß-Diketone Ligand.

A series of acetylacetone-protected lanthanide-titanium-oxo clusters (LTOCs), formulated as [La6Ti(µ3-OH)8(acac)12(CH3O)2(CH3OH)6] (La6Ti; Hacac = acetylacetone) and [Ln9Ti2(µ4-O)(µ3-OH)14(acac)17(CH3O)2(CH3OH)3] [Ln = Eu (Eu9Ti2) and Tb (Tb9Ti2)], were synthesized through the reactions of LnCl3·6H2O (Ln = La, Eu, and Tb), Hacac, Ti(OiPr)4, and triethylamine in methanol. Crystal structural analysis shows that La6Ti exhibits an hourglass-like structure consisting of two La3Ti cubane subunits by sharing one Ti4+ ion, while Eu9Ti2 can be viewed as a combination of four Eu3Ti cubane subunits by sharing three corners and one side. The photoluminescence (PL) measurements show that Tb9Ti2 exhibits excellent PL properties with a high quantum yield (QY) of 34.8%, while Eu9Ti2 only has a QY of 1.4% because of the different photosensitizations of ligands to Eu3+ and Tb3+ ions in the photophysical process.

Asymmetric Cyanosilylation of Aldehydes by a Lewis Acid/Base Synergistic Catalyst of Chiral Metal Clusters.

Metal clusters with well-defined crystal structures are extremely useful for studying the synergistic catalytic effects and associated catalytic mechanisms. In this study, two pairs of chiral lanthanide-transition metal clusters (R)/(S)-Co3Ln2 (Ln = Tb or Dy) were synthesized using Schiff-base ligands [(R)- or (S)-H3L] with multiple Lewis base sites (O sites). The as-prepared (R)/(S)-Co3Ln2 chiral metal clusters exhibited good catalytic functionality in the asymmetric synthesis of chiral cyanohydrins, with high conversions of up to 99% and medium-to-high enantiomeric excess values of up to 78%. The catalysis process followed a mechanism in which the bifunctional metal clusters of (R)/(S)-Co3Ln2, containing Lewis acid sites and Lewis base sites, simultaneously activated the aldehydes and trimethylsilyl cyanide, respectively. Consequently, synergistic catalysis was realized. The enantioselectivity of the different aldehydes and stereochemical configuration of the resulting products are attributed to the formation of a steric chiral pocket via the external chiral ligands on the clusters. In addition, heterogeneous asymmetric cyanosilylation using (R)/(S)-Co3Ln2 chiral metal clusters achieved high chemoselectivity and regioselectivity under mild conditions.

Modification of Multi-Component Building Blocks for Assembling Giant Chiral Lanthanide-Titanium Molecular Rings.

Building blocks with multiple components are promising for the synthesis of complex molecular assemblies, but are rarely available. Herein, we report a modification procedure for a multi-component building block [Ln3 Ti(HSA)6 (SA)4 (H2 O)]- ({Ln3 Ti-SA}, H2 SA=salicylic acid, Ln=Eu/Gd) to form new building blocks {Ln3 Tix -MSA} (H2 MSA=5-methoxysalicylic acid, x=1, 2, 3) by constructing [Ti(MSA)3 ]2- units. The obtained {Ln3 Tix -MSA} can further assemble into a chiral Ln22 Ti14 ring with the formulae [Eu22 Ti14 (MSA)48 (HMSA)22 (CH3 COO)4 (H2 O)10 (iPrOH)] and [Gd22 Ti14 (MSA)46 (HMSA)26 (CH3 COO)4 (H2 O)8 ]. Parallel experiments without Ti4+ result in linear Ln chains. Detailed analysis shows that the [Ti(MSA)4 ]4- unit makes the originally variable Ln chains become available building blocks and the modified [Ti(MSA)3 ]2- further triggers interesting chiral-sorting behavior. Finally, the electronic adsorption and magneto-optic responses of these molecular rings are investigated.

From a Metal-Organic Square to a Robust and Regenerable Supramolecular Self-assembly for Methane Purification.

Porous supramolecular assemblies constructed by noncovalent interactions are promising for adsorptive purification of methane because of their easy regeneration. However, the poor stability arising from the weak noncovalent interactions has obstructed their practical applications. Here, we report a robust and easily regenerated polyhedron-based cationic framework assembled from a metal-organic square. This material exhibits a very low affinity for CH4 and N2 , but captures other competing gases (e.g. C2 H6 , C3 H8 , and CO2 ) with a moderate affinity. These results underpin highly selective separation of a range of gas mixtures that are relevant to natural gas and industrial off-gas. Dynamic breakthrough studies demonstrate its practical separation for C2 H6 /CH4 , C3 H8 /CH4 , CO2 /N2 , and CO2 /CH4 . Particularly, the separation time is ≈11 min g-1 for the C2 H6 /CH4 (15/85 v/v) mixture and ≈49 min g-1 for the C3 H8 /CH4 (15/85 v/v) mixture (under a flow of 2.0 mL min-1 ), respectively, enabling its capability for CH4 purification from light alkanes.