Ternary hybrid CuO-PMA-Ag sub-1 nm nanosheet heterostructures

Multi-component two-dimensional (2D) hybrid sub-1 nm heterostructures could potentially possess many novel properties. Controlling the site-selective distribution of nanoparticles (NPs) at the edge of 2D hybrid nanomaterial substrates is desirable but it remains a great challenge. Herein, we realized for the first time the preparation of ternary hybrid CuO-phosphomolybdic acid-Ag sub-1 nm nanosheet heterostructures (CuO-PMA-Ag THSNHs), where the Ag NPs selectively distributed at the edge of 2D hybrid CuO-PMA sub-1 nm nanosheets (SNSs). And the obtained CuO-PMA-Ag THSNHs as the catalyst exhibited excellent catalytic activity in alkene epoxidation. Furthermore, molecular dynamics (MD) simulations demonstrated that the SNSs interact with Ag NPs to form stable nanoheterostructures. This work would pave the way for the synthesis and broader applications of multi-component 2D hybrid sub-1 nm heterostructures.

Facile synthesis of Ag-CuO/SBA-15 for aerobic epoxidation of olefins with high activity

An efficient 'structure-property' catalyst Ag-CuO/SBA-15 for aerobic epoxidation of olefins was designed and prepared via a simple grinding method, which provided a dynamic assembly driving force to push the precursors into the channels step by step. Partial melting on the precursor particles surface is necessary for synthesizing the Ag-CuO/SBA-15 catalysts. During the thermal grinding process, the partial melting Cu(NO₃)₂ first adhered on AgNO₃ particles surface because the N of AgNO₃ possess stronger interaction with Cu(NO₃)₂ than OH- of SBA-15, then the mixture of melting precursors on AgNO₃ particles surface were sucked into the channels of SBA-15 step by step. Finally, high dispersion of both Ag and CuO nanoparticles were formed in the SBA-15 channels after calcination. The interaction between Ag and CuO, which was characterized by high-resolution transmission electron microscopy, UV-vis and x-ray powder diffraction, enhances the catalytic activity of the catalysts, giving high conversion and selectivity to the epoxides. The reaction mechanism is as follows, the solvent xylene molecule was first oxidized on the Ag surface to form methyl-benzaldehyde (R1), and then moved to the CuO surface to form the peroxidic radical (R2), the peroxidic radical attacked the trans-stilbene C=C bonds on the CuO surface to obtain the epoxides. This synergistic effect shows high activity toward the epoxidation of trans-stilbene.

NiO promoted CuO–NiO/SBA-15 composites as highly active catalysts for epoxidation of olefins

NiO promoted dispersion of CuO in the CuO–NiO/SBA-15 composites, which showed high activity for olefin epoxidation.

Novel Metal Nanomaterials and Their Catalytic Applications

In the rapidly developing areas of nanotechnology, nano-scale materials as heterogeneous catalysts in the synthesis of organic molecules have gotten more and more attention. In this review, we will summarize the synthesis of several new types of noble metal nanostructures (FePt@Cu nanowires, Pt@Fe₂O₃ nanowires and bimetallic Pt@Ir nanocomplexes; Pt-Au heterostructures, Au-Pt bimetallic nanocomplexes and Pt/Pd bimetallic nanodendrites; Au nanowires, CuO@Ag nanowires and a series of Pd nanocatalysts) and their new catalytic applications in our group, to establish heterogeneous catalytic system in "green" environments. Further study shows that these materials have a higher catalytic activity and selectivity than previously reported nanocrystal catalysts in organic reactions, or show a superior electro-catalytic activity for the oxidation of methanol. The whole process might have a great impact to resolve the energy crisis and the environmental crisis that were caused by traditional chemical engineering. Furthermore, we hope that this article will provide a reference point for the noble metal nanomaterials' development that leads to new opportunities in nanocatalysis.

Cu and Boron Doped Carbon Nitride for Highly Selective Oxidation of Toluene to Benzaldehyde

A novel Cu and boron doped graphitic carbon nitride catalyst (Cu-CNB) was synthesized using cheap precursors and systematically characterized. The selective oxidation of toluene proceeded very smoothly over the catalyst at 70 °C using tert-butyl hydroperoxide (TBHP) as the oxidant to exclusively afford benzaldehyde. The catalyst can be used for at least five cycles without decrease in activity and selectivity.

Nanosilver as a new generation of silver catalysts in organic transformations for efficient synthesis of fine chemicals

Silver nanoparticles catalysis has been of great interest in organic synthesis and has expanded rapidly in the past ten years because of nanosilver catalysts' unique reactivity and selectivity, stability, as well as recyclability in catalytic reactions.

Rational design of carbon support to prepare ultrafine iron oxide catalysts for air oxidation of alcohols

The efficient carbon supports change not only the physical but also the chemical properties of iron oxide and create new active sites for the enhancement of catalytic activity in the oxidation of alcohols with air as an oxygen source.

Comparative supercapacitance performance of CuO nanostructures for energy storage device applications

(a)–(c) FE-SEM images of CuO nanoplates on Ni foam, flower-shaped CuO and bud-shaped CuO. (d) Specific capacitance and (d) and (e) Ragone plots of power density vs. energy density according to CuO electrodes in an asymmetrical device.

Synthesis of a Fe3O4–CuO@meso-SiO2 nanostructure as a magnetically recyclable and efficient catalyst for styrene epoxidation

A novel Fe₃O₄–CuO@meso-SiO₂ composite was fabricated as a magnetically recyclable and efficient catalyst for olefin epoxidation.