Metal–organic gels as functionalisable supports for catalysis

Xia

et al. 2015

Sci Rep

Hierarchical heteronuclear metal-organic gels (MOGs) based on iron (Fe) and aluminium (Al) metal-organic framework (MOF) backbones bridged by tri-carboxylate ligands have firstly been synthesized by simple solvothermal method. Monometallic MOGs based on Fe or Al give homogenous monoliths, which have been tuned by introduction of heterogeneity in the system (mismatched growth). The developed gels demonstrate that surface areas, pore volumes and pore sizes can be readily tuned by optimizing heterogeneity. The work also elaborates effect of heterogeneity on size of MOG particles which increase substantially with increasing heterogeneity as well as obtaining mixed valence sites in the gels. High surface areas (1861 m2/g) and pore volumes (9.737 cc/g) were obtained for heterogeneous gels (0.5Fe-0.5Al). The large uptakes of dye molecules (290 mg/g rhodamine B and 265 mg/g methyl orange) with fast sorption kinetics in both neutral and acidic mediums show good stability and accessibility of MOG channels (micro and meso-/macropores), further demonstrating their potential applications in catalysis and sorption of large molecules.

mentioning

confidence: 99%

Hierarchical Heteroaggregation of Binary Metal-Organic Gels with Tunable Porosity and Mixed Valence Metal Sites for Removal of Dyes in Water

Xia

et al. 2015

Sci Rep

Chemistry An Asian Journal

“…A similar study on Pd II ‐functionalized metallogels obtained by the post‐modification of a Fe III ‐metallogel matrix was realized by Zhang, Su, and co‐workers, and exhibited improved catalytic activity and recyclability in Suzuki–Miyaura C−C coupling reactions (Figure ) . In contrast to the aforementioned examples with organogel precursors for the gel matrix, ligand 10 first coordinated with Fe(NO 3 ) 3 ⋅ 9 H 2 O to generate an O−Fe bond that resulted the formation of metallogels 10 /Fe, then the diphenylphosphrous group or the imidazole N atom of 10 further strongly coordinates to [Pd(cod)Cl 2 ] due to hard and soft acids and bases (HSAB) matching to provide active catalytic sites.…”

Section: Metallogels In Catalysismentioning

confidence: 58%

Recent Advances in Supramolecular Gels and Catalysis

Fang

Zhang

et al. 2018

125

Over the past two decades, supramolecular gels have attracted significant attention from scientists in diverse research fields and have been extensively developed. This review mainly focuses on the significant achievements in supramolecular gels and catalysis. First, by incorporating diverse catalytic sites and active organic functional groups into gelator molecules, supramolecular gels have been considered as a novel matrix for catalysis. In addition, these rationally designed supramolecular gels also provide a variety of templates to access metal nanocomposites, which may function as catalysts and exhibit high activity in diverse catalytic transformations. Finally, as a new kind of biomaterial, supramolecular gels formed in situ by self-assembly triggered by catalytic transformations are also covered herein.

“…Metal–organic gelation processes to realize hierarchical micro‐ and mesoporous metal–organic aerogels (MOAs) combining the features of MOFs and aerogels (e.g., low density, monolithic) have been thoroughly studied by Zhang and co‐workers and Su and co‐workers ( Figure ) . A facile two‐step gelation process of microporous crystalline MOF particles under appropriate adjustment of reacting temperature integrate MOF nanoparticles into a gel matrix.…”

Section: Fabrication Strategies To Mesoporositymentioning

confidence: 99%

Mesoporous Metal–Organic Frameworks: Synthetic Strategies and Emerging Applications

Liu

Zou

Zhu

et al. 2018

Small

Self Cite

159

117

Metal-organic frameworks (MOFs) have attracted much attention over the past two decades due to their highly promising applications not only in the fields of gas storage, separation, catalysis, drug delivery, and sensors, but also in relatively new fields such as electric, magnetic, and optical materials resulting from their extremely high surface areas, open channels and large pore cavities compared with traditional porous materials like carbon and inorganic zeolites. Particularly, MOFs involving pores within the mesoscopic scale possess unique textural properties, leading to a series of research in the design and applications of mesoporous MOFs. Unlike previous Reviews, apart from focusing on recent advances in the synthetic routes, unique characteristics and applications of mesoporous MOFs, this Review also mentions the derivatives, composites, and hierarchical MOF-based systems that contain mesoporosity, and technical boundaries and challenges brought by the drawbacks of mesoporosity. Moreover, this Review subsequently reveals promising perspectives of how recently discovered approaches to different morphologies of MOFs (not necessarily entirely mesoporous) and their corresponding performances can be extended to minimize the shortcomings of mesoporosity, thus providing a wider and brighter scope of future research into mesoporous MOFs, but not just limited to the finite progress in the target substances alone.