Crystal Growth Blocking Strategy Enabling Efficient Solvent-Free Synthesis of Hierarchical UiO-66 for Large-Molecule Catalysis

Metal–organic frameworks (MOFs) with rich hierarchical structures have attracted great attention in processes with large molecules, such as catalysis and adsorption. However, efficiently and cost-effectively fabricating hierarchical MOFs with robust stability remains challenging. Herein, we report a crystal growth blocking strategy to prepare hierarchical UiO-66 by a solvent-free method. The addition of FeCl3 to the synthetic system blocks the overgrowth of UiO-66 crystals and limits the particle size to around just 12 nm. After the removal of Fe by ethanol treatment, these small particles loosely aggregate and gain intercrystalline mesopores. The optimal sample Mes-UiO-66 exhibits a well-developed hierarchical structure, the BET surface area reaches 1161.9 m2 g–1, and the mesopore volume attains a state-of-the-art 1.21 cm3 g–1. The superior catalytic performance and the robust stability of Mes-UiO-66 are demonstrated by the oxidation of DBT, in which the DBT conversion surpasses 99% and shows a slight decrease after five cycles. Our finding may provide a novel platform for efficiently fabricating hierarchical MOFs for large-molecule catalysis

Biomass wood-derived efficient Fe–N–C catalysts for oxygen reduction reaction

International audienc

Enhancement of catalytic performance in the benzylation of benzene with benzyl alcohol over hierarchical mordenite

International audienc

Hierarchization of Mordenite as NiW Sulfide Catalysts Support: Towards Efficient Hydrodesulfurization

International audienc

Study on structural and functional properties of porous SiO 2 core‐shell construction/polyethylene nanocomposites with enhanced interfacial interaction

International audienceAbstract The addition of inorganic particles can endow polymer matrices with different new features, thereby realizing an optimization to the structural and functional properties of composite. The overall properties of composites are greatly influenced by both fillers dispersion and fillers‐polymer interfacial interaction. However, to simultaneously improve these mentioned two issues is still a critical challenge in the field of polymer‐based nanocomposite. Herein, a typical core‐shell structured mesoporous silica‐coated silica (SiO 2 @mSiO 2 ) construction was successfully synthesized by using a bi‐phase method. The SiO 2 @mSiO 2 filled polyethylene (PE) nanocomposite was fabricated through a precisely controlled melt‐mixing approach. Benefiting from the additional mesoporous SiO 2 shell, both the dispersion of SiO 2 @mSiO 2 and the SiO 2 @mSiO 2 ‐PE matrix interfacial interaction are improved. Moreover, the stress–strain behavior, temperature‐dependent mechanical property, thermal stability, and electrical insulating property of SiO 2 @mSiO 2 /PE composite were studied in detail. It is found that SiO 2 @mSiO 2 core‐shell nanoparticles are capable of not only making a balance between the strength and toughness of the PE‐based composite, but also improving the thermal stability of the composite. In addition, the SiO 2 @mSiO 2 /PE composite exhibited an enhanced breakdown strength (256.4 MV·m −1 ) when filled with as small as 1 wt% SiO 2 @mSiO 2 , which is 108% higher than neat PE. All these optimized features are attributed to the well‐designed core‐shell structure. These experimental results provide a promising way to design and fabricate future advanced composite with excellent structural and functional properties in the future

Ionic Exchange of Metal−Organic Frameworks for Constructing Unsaturated Copper Single‐Atom Catalysts for Boosting Oxygen Reduction Reaction

International audienc

Assembly of Janus complex with low-cost and salt rejection for solar-thermal water evaporation

International audienc

Efficient industrial-current-density acetylene to polymer-grade ethylene via hydrogen-localization transfer over fluorine-modified copper

International audienceAbstract Electrocatalytic acetylene semi-hydrogenation to ethylene powered by renewable electricity represents a sustainable pathway, but the inadequate current density and single-pass yield greatly impedes the production efficiency and industrial application. Herein, we develop a F-modified Cu catalyst that shows an industrial partial current density up to 0.76 A cm −2 with an ethylene Faradic efficiency surpass 90%, and the maximum single-pass yield reaches a notable 78.5%. Furthermore, the Cu-F showcase the capability to directly convert acetylene into polymer-grade ethylene in a tandem flow cell, almost no acetylene residual in the production. Combined characterizations and calculations reveal that the Cu δ+ (near fluorine) enhances the water dissociation, and the generated active hydrogen are immediately transferred to Cu 0 (away from fluorine) and react with the locally adsorbed acetylene. Therefore, the hydrogen evolution reaction is surpassed and the overall acetylene semi-hydrogenation performance is boosted. Our findings provide new opportunity towards rational design of catalysts for large-scale electrosynthesis of ethylene and other important industrial raw

Rapid Synthesis of Metal–Organic Frameworks MIL-101(Cr) Without the Addition of Solvent and Hydrofluoric Acid

Metal–organic frameworks MIL-101­(Cr) have been rapidly synthesized by solid-phase reaction without the addition of solvent and hydrofluoric acid at 220 °C in 4 h. The obtained MIL-101­(Cr) material exhibited superior catalytic activity in the oxidation of cyclohexene

Interfacial Cladding Engineering Suppresses Atomic Thermal Migration to Fabricate Well‐Defined Dual‐Atom Electrocatalysts

Abstract As an emerging frontier, dual‐atom catalysts (DACs) have sparked broad interest in energy catalysis, however the undesired thermal atomic migration during synthesis process pose significant challenge in enabling further applications. Herein, an interfacial cladding strategy is reported to construct monodispersed dual‐atom metal sites (metal = Fe, Cu, or Ir), derived from metal dimer molecule functionalized metal‐organic frameworks. First, metal dimer molecule is immobilized at the surface of cubic ZIF‐8 by the interfacial cladding of polydopamine, thus preventing the potentially thermal migration of metal atoms during pyrolysis. Then, the paired metal atoms are anchored onto a hollow carbon nanocage and achieve nitrogen coordinated dual‐atom metal sites after annealing at 900 °C. Representatively, the resultant dual Fe catalysts exhibit remarkable activity for electrocatalytic oxygen reduction reaction with half‐wave potential of 0.951 and 0.816 V in alkaline and acidic media, respectively. The findings open up an avenue for the rational design of dual‐atom catalysts