Multifunctional Polymolybdate-Based Metal-Organic Framework as an Efficient Catalyst for the CO2 Cycloaddition and as the Anode of a Lithium-Ion Battery

Dynamic Metal-Iodide Bonds in a Tetracoordinated Cadmium-Based Metal-Organic Framework Boosting Efficient CO2 Cycloaddition under Solvent- and Cocatalyst-Free Conditions

Due to the inherent thermodynamic stability and kinetic inertness of CO₂, heterogeneous catalytic conversion of CO₂ to cyclic carbonates often requires harsh operating conditions, high temperature and high pressure, and the addition of cocatalysts. Therefore, the development of efficient heterogeneous catalysts under cocatalyst-free and mild conditions for CO₂ conversion has always been a challenge. Herein, an infrequent tetracoordinated Cd-MOF was synthesized and used to catalyze CO₂ cycloaddition reactions efficiently without the addition of any cocatalyst, and its catalytic mechanism was systematically investigated through a series of experiments, including fluorescence analysis, X-ray photoelectron spectroscopy, microcalorimetry, and density functional theory (DFT) calculation. Cd-MOF features a 3D supermolecule structure with 1D 11.6 × 7.7 Ų channels, and the abundant Lewis acid/base and I^- sites located in the confined channel boost efficient CO₂ conversion with a maximum yield of 98.2% and a turnover number value of 1080.11 at 60 °C and 0.5 MPa, far surpassing most pristine MOF-based catalytic systems. A combined experimental and DFT calculation demonstrates that the exposed Cd(II) Lewis acid sites rapidly participate in coordination to activate the epoxides, and the resulting large steric hindrance facilitates leaving of the coordinated iodide ions in a reversibly dynamic fashion convenient for the rate-determining step ring-opening as a strong nucleophile. Such a pristine MOF catalyst with self-independent catalytic ring-opening overcomes the complicated operation limitation of the traditional cocatalyst-free MOF systems based on encapsulating/postmodifying cocatalysts, providing a whole new strategy for the development of simple, green, and efficient heterogeneous catalysts for CO₂ cycloaddition.

Two POM-based compounds containing Zn-capped Keggin anions as decent heterogeneous catalysts for sulfur oxidation and cycloaddition of CO2 reactions

Carbon dioxide (CO2) and the combustion of sulfide in gasoline are the main causes of air pollution. Great deal of attention has been committed to solving the problem and the...

A robust heterogeneous Co-MOF catalyst in azide–alkyne cycloaddition and Friedel–Crafts reactions as well as hydrosilylation of alkynes

A robust Co(ii) MOF with high stability was prepared to promote the azide–alkyne cycloaddition reaction, Friedel–Crafts reactions of indoles and hydrosilylation reactions of alkynes.

Two new isolated Zn-ε-Keggin clusters modified by conjugated organic ligands with decent electrocatalytic and third-order NLO properties

Compound 2 is the first isolated Zn₅PMo₁₂ cluster, and the two Zn-ε-Keggin-based compounds display excellent electrocatalytic and third-order NLO properties.