Preparation of CuO@Mesoporous SiO2 Via Calcining Nanocasted Metal Organic Frameworks (MOFs) for Styrene Oxidation Reaction

A mesoporous silica bearing uniformly distributed copper oxide nanoparticles (CuO@mesoporous SiO2) was prepared through silica nanocasting copper metal organic frameworks (MOFs) followed by calcination. The nanocasting filled the micropores of MOFs with silica and then, the calcination removed the organic linker in MOFs and converted copper metal ions into CuO particles, resulting in the CuO@mesoporous SiO2 architecture. The characterization results indicated that the final product basically maintained the original MOF morphology and the mesoporous silica effectively prevented the aggregation of nanoparticles. In addition, the CuO@mesoporous SiO2 exhibited a superior activity for catalyzing the oxidation of styrene, which could be attributed to the fact that the dispersed CuO particles in mesoporous silica provided more accessible catalytic sites and better stability. This work provides a new strategy to prepare nanoparticles@mesoporous silica with adjustable morphology structure, which has a promising potential in the field of heterogeneous catalysis.

Selective Styrene Oxidation to Benzaldehyde over Recently Developed Heterogeneous Catalysts

The selective oxidation of styrene under heterogeneous catalyzed conditions delivers environmentally friendly paths for the production of benzaldehyde, an important intermediate for the synthesis of several products. The present review explores heterogeneous catalysts for styrene oxidation using a variety of metal catalysts over the last decade. The use of several classes of supports is discussed, including metal–organic frameworks, zeolites, carbon materials and silicas, among others. The studied catalytic systems propose as most used oxidants tert-butyl hydroperoxide, and hydrogen peroxide and mild reaction conditions. The reaction mechanism proceeds through the generation of an intermediate reactive metal–oxygen species by catalyst-oxidant interactions. Overall, most of the studies highlight the synergetic effects among the metal and support for the activity and selectivity enhancement.

Catalytic Performance of TiO2–Carbon Mesoporous-Derived from Fish Bones in Styrene Oxidation with Aqueous Hydrogen Peroxide as an Oxidant

The catalytic performance of titania-supported carbon mesoporous-derived from fish bones (TiO2/CFB) has been investigated in styrene oxidation with aqueous H2O2. The preparation steps of (TiO2/CFB) catalyst involved the carbonization of fish bones powder at 500 °C for 2 h. followed by impregnation of titania using titanium(IV) isopropoxide (500 µmol) precursor, and calcined at 350 °C for 3 h. The physical properties of the adsorbents were characterized using Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and nitrogen adsorption-desorption studies. The catalytic test was carried out using styrene oxidation with H2O2 as an oxidant at room temperature for 24 h. Its catalytic activity was compared with Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts. It is demonstrated that the catalytic activity of TiO2/CFB catalyst has the highest compared to Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts in the oxidation of styrene with styrene conversion ~23% and benzaldehyde selectivity ~90%. Kinetics of TiO2/CFB catalyzed oxidation of styrene has been investigated and mechanism for oxidation of styrene has been proposed. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Controlling Product Selectivity with Nanoparticle Composition in Tandem Chemo-Biocatalytic Styrene Oxidation

The combination of heterogeneous catalysis and biocatalysis into one-pot reaction cascades is a potential approach to integrate enzymatic transformations into existing chemical infrastructure. Peroxygenases, which can achieve clean C-H activation,...

One-pot synthesis of Ag@silicalite-1 with different silver amine complexes and the performance for styrene oxidation

A facile one-pot strategy was used to successfully synthesize Ag@silicalite-1 using different silver amine complex mixtures as precursors via a hydrothermal synthesis method. Ag@silicalite-1 was characterized by X-ray diffraction (XRD),...