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

MOF-Derived PdCo and PdMn Systems as Versatile Catalysts in Alkyne Semihydrogenation

This study investigates the structure and catalytic properties of bimetallic nanocomposites derived from PdCo- and PdMn-based metal-organic frameworks. These materials, synthesized via chemical (Q) and thermal treatments (T), resulted in PdCo-QT and PdMn-QT catalysts containing Pd-based nanoparticles modified with Co or Mn and supported on N-doped carbon. Detailed characterization techniques confirm these complex structures, including high-resolution transmission electron microscopy, scanning transmission electron microscopy energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. The catalytic performances of these materials were evaluated for the selective semihydrogenation of phenylacetylene and 4-octyne under soft conditions (1 H2 bar, room temperature) in batch reactors, demonstrating very high selectivity (≥95 mol %) toward alkenes at high conversion levels (≥94 mol %). Moreover, they displayed significant stability after five catalytic cycles with minimal leaching and highly competitive values of alkyne productivity in the semihydrogenation of phenylacetylene. The study also explored the potential of these catalysts in continuous gas-phase reactions, where PdCo-QT demonstrated remarkable catalytic activity and selectivity with a high gas hourly space velocity.

State-of-the-Art, Insights, and Perspectives for MOFs-Nanocomposites and MOF-Derived (Nano)Materials

Composite structures created from metal‒organic framework (MOF) matrices are reviewed in this work. Depending on the nature of the second component apart from the MOF platform, several synergistic properties may arise; at the same time, the initial features of the single constituent materials are usually maintained, and individual shortcomings are mitigated. Currently, timely energy and environmental challenges necessitate the quest for more advanced materials and technologies. Significant developments in MOF-nanocomposites have enabled their application across a wide range of modern and traditional fields. This review demonstrates in an exhaustive and critical way a broad range of MOF-based nanocomposites, namely, MOF/perovskite nanoparticles (NPs), MOF/metal (non-iron) oxide NPs, MOF/Fe3O4 NPs, MOF/metal chalcogenide NPs, MOF/metal NPs, and MOF/carbon-based materials, as well as nanocomposites of MOFs with other semiconductor NPs. Key points related to the synthesis, characterization, and applications of these materials are provided. Depending on their configuration, the composites under discussion can be applied in domains such as photoelectrochemical sensing, antibiotic/dye degradation, optoelectronics, photovoltaics, catalysis, solar cells, supercapacitors, batteries, water remediation, and drug loading. Sometimes, MOFs can undergo certain processes (e.g. pyrolysis) and act as precursors for composite materials with appealing characteristics. Therefore, a special section in the manuscript is devoted to MOF-derived NP composites. Toward the end of the text, we conclude while also describing the challenges and possibilities for further investigations in the umbrella of material categories analyzed herein. Despite the progress achieved, key questions remain to be answered regarding the relationships among the morphology, properties, and polyvalent activity of these materials. The present work aims to shed light on most of their aspects and innovative prospects, facilitating a deeper comprehension of the underlying phenomena, functionality, and mechanistic insights governing their behavior.

Efficient Alkyne Semihydrogenation Catalysis Enabled by Synergistic Chemical and Thermal Modifications of a PdIn MOF

Recently, there has been a growing interest in using MOF templating to synthesize heterogeneous catalysts based on metal nanoparticles on carbonaceous supports. Unlike the common approach of direct pyrolysis of PdIn-MOFs at high temperatures, this work proposes a reductive chemical treatment under mild conditions before pyrolysis (resulting in PdIn-QT). The resulting material (PdIn-QT) underwent comprehensive characterization via state-of-the-art aberration-corrected electron microscopy, N2 physisorption, X-ray absorption spectroscopy, Raman, X-ray photoelectron spectroscopy, and X-ray diffraction. These analyses have proven the existence of PdIn bimetallic nanoparticles supported on N-doped carbon. In situ DRIFT spectroscopy reveals the advantageous role of indium (In) in regulating Pd activity in alkyne semihydrogenation. Notably, incorporating a soft nucleation step before pyrolysis enhances surface area, porosity, and nitrogen content compared to direct MOF pyrolysis. The optimized material exhibits outstanding catalytic performance with 96% phenylacetylene conversion and 96% selectivity to phenylethylene in the fifth cycle under mild conditions (5 mmol phenylacetylene, 7 mg cat, 5 mL EtOH, R.T., 1 H2 bar).

Heterometallic palladium-iron metal-organic framework as a highly active catalyst for cross-coupling reactions

Palladium-based metal-organic frameworks (Pd-MOFs) are an emerging class of heterogeneous catalysts extremely challenging to achieve due to the facile leaching of palladium and its tendency to be reduced. Herein, Pd(ii) was successfully incorporated in the framework of a MOF denoted as MUV-22 using a solvent assisted reaction. This stable MOF, with square-octahedron (soc) topology as MIL-127, and a porosity of 710 m² g^-1, is highly active, selective, and recyclable for the Suzuki-Miyaura allylation of aryl and alkyl boronates as exemplified with the coupling between cinnamyl bromide and Me-Bpin, a typically reluctant reagent in cross-coupling reactions.

1T-MoS2 catalysed reduction of nitroarenes and a one-pot synthesis of imines

An expedient synthesis of aromatic amines and imines via the reduction of nitroaromatics using 1T-MoS2 as a heterogeneous catalyst.