Publications by authors named "En-Hui Yuan"

Zeolites are important classes of crystalline materials and possess well-defined channels and cages with molecular dimensions. They have been extensively employed as heterogeneous catalysts and gas adsorbents due to their relatively large specific surface areas, high pore volumes, compositional flexibility, definite acidity, and hydrothermal stability. The zeolite synthesis normally undergoes high-temperature hydrothermal treatments with a relatively long crystallization time, which exhibits low synthesis efficiency and high energy consumption.

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Highly active nonprecious-metal single-atom catalysts (SACs) toward catalytic transfer hydrogenation (CTH) of α,β-unsaturated aldehydes are of great significance but still are deficient. Herein, we report that Zn-N-C SACs containing Zn-N moieties can catalyze the conversion of cinnamaldehyde to cinnamyl alcohol with a conversion of 95.5% and selectivity of 95.

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As an important organic intermediate, benzonitrile (BN) is widely involved in organic synthetic chemistry and pharmaceutical and dyestuff industries. However, the exploration of a more efficient and controllable synthesis technique and the corresponding greener catalysts for the synthesis of BN still poses a great challenge. Herein, with multimetallic two-dimensional conductive metal-organic frameworks (2D cMOF) as anodic electrocatalysts, we develop a green, convenient, and highly efficient electrochemical synthesis strategy for BN.

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Mesoporous nanospheres are highly regarded for their applications in nanomedicine, optical devices, batteries, nanofiltration, and heterogeneous catalysis. In the last field, the dendritic morphology, which favors molecular diffusion, is a very important morphology known for silica, but not yet for carbon. A one-pot, easy, and scalable co-sol-gel route by using the triphasic resol-surfactant-silica system is shown to yield the topologies of dendritic and core-shell-corona mesoporous sister nanospheres by inner radial phase speciation control on a mass-transfer-limited process, depending on the relative polycondensation rates of the resol polymer and silica phases.

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Following the structural concept of copper-containing proteins in which dinuclear copper centers are connected by hydroxide bridging ligands, a bidentate copper(II) complex has been incorporated into nano-confined MCM-41 silica by a multistep sequential grafting technique. Characterization by a combination of EPR spectroscopy, X-ray photoelectron spectroscopy (XPS), UV/Vis spectroscopy, IR spectroscopy , and solid-state (13)C and (29)Si cross-polarization magic-angle spinning (CP-MAS) NMR suggests that dinuclear Cu complexes are bridged by hydroxide and other counterions (chloride or perchlorate ions), similar to the situation for EPR-undetectable [Cu(II)···Cu(II)] dimer analogues in biological systems. More importantly, a dynamic mononuclear-dinuclear equilibrium between different coordination modes of copper is observed, which strongly depends on the nature of the counterions (Cl(-) or ClO(4)(-)) in the copper precursor and the pore size of the silica matrix (the so-called confinement effect).

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