Oxidation Of Cinnamyl Alcohol Research Articles

TEMPO immobilized polymeric Janus dumbbell: Assembly and catalysis at liquid-liquid interface

Pickering interfacial catalysts (PICs) have emerged as a promising solution for simultaneously enhancing and catalyzing liquid-liquid biphasic reactions. In this study, we successfully synthesized dumbbell-shaped Janus structured polymeric nanoparticles with one side anchored imidazolium-TEMPO (im-C4-TEMPO@JPP) as Pickering interfacial catalyst for the oxidation of alcohols using the Anelli-Montanari reaction system. In the Pickering emulsion system, the im-C4-TEMPO@JPPs particles are assembled at the W/O interface due to the hydrophilicity of imidazolium-TEMPO anchored lobe which enables excellent amphiphilic character of the polymeric Janus dumbbell. Moreover, the im-C4-TEMPO@JPPs particles reduce the interfacial tension from 27.82 to 18.43 mN/m. This excellent interfacial adsorption capacity of im-C4-TEMPO@JPPs strongly stabilizes the water/dichloromethane Pickering emulsion over two months (emulsion volume fraction >90 %), thus providing an efficient reaction platform for liquid-liquid biphasic reactions. As a result, the constructed Pickering emulsion system efficiently catalyzes the oxidation of cinnamyl alcohol to cinnamaldehyde under static conditions. After 1 hour of reaction, the conversion of cinnamyl alcohol achieved 97.1 % with a selectivity of 99 %, nearly the same level relative to stirring intensified biphasic reaction. Hence, this novel PIC effectively improves the efficiency and sustainability of liquid-liquid biphasic catalytic reactions.

The Kinetics and Mechanism of Oxidation of Cinnamyl Alcohol by N-Chloro p-toluene Sulphonamide (Chloramine-T) in Acid Perchlorate Medium

The Kinetics and Mechanism of Oxidation of Cinnamyl Alcohol by N-Chloro p-toluene Sulphonamide (Chloramine-T) in Acid Perchlorate Medium

Molybdate intercalated magnesium aluminium hydrotalcite as a potential catalyst for the oxidation of cinnamyl alcohol

Molybdate intercalated magnesium aluminium hydrotalcite as a potential catalyst for the oxidation of cinnamyl alcohol

Isolated PdO sites on SiO2-supported NiO nanoparticles as active sites for allylic alcohol selective oxidation

Silica-supported NiO nanoparticles as hosts for isolated PdO catalytic sites. Isolate PdO is confirmed as the species responsible for the chemoselective oxidation of cinnamyl alcohol to cinnamaldehyde by operando X-ray absorption spectroscopy.

Synthesis, spectral characterization, and catalytic efficiency of aroylhydrazone-based Cu(ii) complexes

Copper(ii) complexes of tridentate aroylhydrazones were synthesized. The prepared copper complexes were found to have potential for cinnamyl alcohol oxidation.

Cover Feature: Photothermal Oxidation of Cinnamyl Alcohol with Hydrogen Peroxide Catalyzed by Gold Nanoparticle/Antimony‐Doped Tin Oxide Nanocrystals (Chem. Eur. J. 46/2022)

Gold nanoparticle-loaded, antimony-doped tin oxide nanocrystals (Au/ATO NCs) show thermally activated catalytic activity for the oxidation of cinnamyl alcohol to cinnamaldehyde by hydrogen peroxide. Light irradiation (λex>660 nm, ∼0.5 sun) of Au/ATO NCs gives rise to a more than twofold increase in the rate of reaction with ∼95 % selectivity. Kinetic analyses indicated that the striking enhancement of the reaction stems from the rise in the temperature near the catalyst surface of ∼30 K due to the photothermal effect of the ATO NCs. More information can be found in the Research Article by H. Tada and co-workers (DOI: 10.1002/chem.202201653).

Photothermal Oxidation of Cinnamyl Alcohol with Hydrogen Peroxide Catalyzed by Gold Nanoparticle/Antimony-Doped Tin Oxide Nanocrystals.

Gold nanoparticles with different mean sizes were formed on antimony-doped tin oxide nanocrystals by the temperature-varied deposition-precipitation method (Au/ATO NCs). Au/ATO NCs possess strong absorption in the near-infrared region due to Drude excitation in addition to the localized surface plasmon resonance (LSPR) of AuNPs around 530 nm. Au/ATO NCs show thermally activated catalytic activity for the oxidation of cinnamyl alcohol to cinnamaldehyde by hydrogen peroxide. The catalytic activity increases with a decrease in the mean Au particle size (dAu ) at 5.3 nm≤dAu ≤8.2 nm. Light irradiation (λex >660 nm, ∼0.5 sun) of Au/ATO NCs increases the rate of reaction by more than twice with ∼95 % selectivity. Kinetic analyses indicated that the striking enhancement of the reaction stems from the rise in the temperature near the catalyst surface of ∼30 K due to the photothermal effect of the ATO NCs.

Transition Metal Ions as Catalysts for Oxidation of Cinnamyl Alcohol - A Green Initiative

Transition Metal Ions as Catalysts for Oxidation of Cinnamyl Alcohol - A Green Initiative

Gold Nanoparticles Supported on Poly(2,6‐dimethyl‐1,4‐phenylene oxide) as Robust, Selective and Cost‐Effective Catalyst for Aerobic Oxidation and Direct Oxidative Esterification of Alcohols

AbstractA new catalytic system based on gold nanoparticles (AuNPs) incarcerated in poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) matrix has been synthesized and successfully tested in aerobic oxidation of alkyl alcohols. PPO is a cheap and commercially available polymer, showing nanoporous morphology, high glass transition temperature (Tg =220 °C), semi‐crystallinity, excellent thermal stability, and interesting chemo‐physical properties. The synthesis of the AuNPs‐PPO catalyst is simple, cost‐effective and allows a fine control of the gold concentration, as well as an optimal dispersion of 7–8 nm sized AuNPs in the polymer matrix. AuNPs‐PPO is an efficient, robust and selective catalyst active in the aerobic oxidation and oxidative esterification of alcohols in water under mild reaction conditions (35 °C, atmospheric pressure of oxygen). The testing of AuNPs‐PPO in aerobic oxidation of 1‐phenylethanol to acetophenone, as a benchmark reaction, highlighted that this gold catalyst exhibits activity values among the highest so far reported for polymer‐supported AuNPs under mild reaction conditions. The oxidation of primary alcohols, such as benzyl and cinnamyl alcohols, could be addressed to the corresponding aldehyde or carboxylate derivatives. Alkyl cinnamates were obtained with efficiency in the one‐pot aerobic oxidation of cinnamyl alcohol in the presence of alkyl alcohols, such as n‐butanol or n‐hexanol. The role of the polymer matrix and the reaction conditions on both activity and selectivity of the AuNPs‐PPO catalyst were also investigated and discussed.

Cover Feature: Engineering of Cation Occupancy of CoFe2O4 Oxidation Catalysts by Nanosecond, Single‐Pulse Laser Excitation in Water (ChemCatChem 10/2022)

The Cover Feature illustrates the pulsed laser defect engineering in liquid (PuDEL) of CoFe2O4-nanoparticles. In their Research Article, S. Zerebecki et al. show the pulsed laser induces rapid particle heating which resulted in the generation or healing of defects (e.g. stacking faults) depending on the starting material. The method was used to tune the cation occupancy in CoFe2O4 under constant Co:Fe ratio which was determined by Mössbauer spectroscopy and correlated with the conversion in catalytic cinnamyl alcohol oxidation. More information can be found in the Research Article by S. Zerebecki et al.

Ruthenium on α-Ni(OH)2 as potential catalyst for anisole hydrotreating and cinnamyl alcohol oxidation

Ruthenium on α-Ni(OH)2 as potential catalyst for anisole hydrotreating and cinnamyl alcohol oxidation

Engineering of Cation Occupancy of CoFe2O4 Oxidation Catalysts by Nanosecond, Single‐Pulse Laser Excitation in Water

AbstractDue to the variability of the cation occupancy of octahedral and tetrahedral sites, spinel ferrites and cobaltites are particularly interesting to investigate activity trends in oxidation catalysis. Yet, the preparation of the respective catalyst series remains challenging. We employed pulsed laser defect engineering of CoFe2O4 nanoparticles in water to gradually alter the cation occupancy of octahedral and tetrahedral sites by single laser pulses and study its effect on cinnamyl alcohol oxidation. Three CoFe2O4 catalysts from different synthesis methods resembling different initial site occupancy were chosen as starting materials. The laser‐induced randomization of the cation occupancy was verified by Mössbauer spectroscopy and linearly correlated with the conversion of cinnamyl alcohol while the size and Co : Fe ratio was maintained during laser processing. The study solidifies the importance of octahedral Co3+‐sites and the feasibility of pulsed laser processing for altering the cation occupancy and related crystallographic defect density in oxidation catalysis.

Catalytic Activity of CuFe2O4 Spinel Oxide for Liquid‐Phase Oxidation of Cinnamyl Alcohol

AbstractCuFe2O4 spinel oxide catalyst was synthesized by sol–gel and co‐precipitation methods for liquid phase oxidation of Cinnamyl alcohol (CnOH) to Cinnamaldehydes (CnHO) using tert‐Butyl hydroperoxide (TBHP) as oxidising agent. Spinel oxide catalyst was characterized by different techniques such as X‐ray diffraction (XRD), N2 adsorption‐desorption, BET surface area, and X‐ray photoelectron spectroscopy (XPS) to understand the structural, physical properties and oxidation state of the catalyst. The result shows that catalyst prepared by sol‐gel method was found higher surface area and smaller crystalline size than co‐precipitation method. XPS data confirm the formation of Cu2+ in the spinel which helps to improve the catalytic activity of oxidation. This reaction follows radical mechanism, and exhibited 76.7 % of CnOH conversion and 68.4 % of CnHO, and 24.8 % benzaldehyde (benzald) selectivity using TBHP at 60 °C. Kinetic data reveal that 41.2 kJ/mol of activation energy for the reaction. The higher activity of spinel oxide catalyst could be due synergetic effect of spinel (88 %) and oxides (12 %) formed in the catalyst, which helps to provide the oxygen during reaction. The contribution of Cu2+ is higher in sol‐gel than co‐precipitation, which may provide the better reactivity of catalyst. This work helps to select the effective and cost‐effective catalyst for the oxidation of CnOH.

Atomically Defined Undercoordinated Copper Active Sites over Nitrogen-Doped Carbon for Aerobic Oxidation of Alcohols.

Selective aerobic oxidation of alcohols offers an attractive means to address challenges in the modern chemical industry, but the development of non-noble metal catalysts with superior efficacy for this reaction remains a grand challenge. Here, this study reports on such a catalyst based on atomically defined undercoordinated copper atoms over nitrogen-doped carbon support as an efficient, durable, and scalable heterogeneous catalyst for selective aerobic oxidation of alcohols. This catalyst exhibits extremely high intrinsic catalytic activity (TOF of 7692 h-1 ) in the oxidation of cinnamyl alcohol to afford cinnamaldehyde, along with exceptional recyclability (at least eight cycles), scalability, and broad substrate scope. DFT calculations suggest that the high activity derives from the low oxidation state and the unique coordination environment of the copper sites in the catalyst. These findings pave the way for the design of highly active and stable single atom catalysts to potentially address challenges in synthetic chemistry.

Bimetallic Au-Pd/α-MoO3 Catalyst with High Oxygen Vacancies for Selective Oxidation of Cinnamyl Alcohol

Supported Au-Pd nanoparticles (NPs) have been extensively studied in alcohol oxidation reactions. However, few studies use reducible metal oxides as support, which can activate oxygen molecules and boost the selectivity of the reaction. In this work, Au-Pd NPs were supported on α-MoO3 and evaluated in the selective oxidation of cinnamyl alcohol without solvent. The Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray photoemission spectroscopy (XPS) analyses showed that the catalyst is richer in oxygen vacancies than the support, being probably responsible for the stability of the NPs (average size 4.62 ± 0.15 nm) and the high conversion and selectivity for the oxidation of cinnamyl alcohol. Furthermore, experiments have shown that the Au:Pd molar ratio influences the catalytic performance and can be optimized by controlling temperature, pressure, and reaction time. The catalyst proved to be active and selective for cinnamaldehyde in short reaction times. It showed satisfactory performance at 30 min and its best activity at 1 h with 94% conversion and 87% selectivity, without loss of activity and selectivity after four runs under the same reaction conditions.

Kinetics and Mechanism of Ruthenium(III) Chloride Catalyzed Oxidation of Cinnamyl Alcohol by Thallium(III) in Acid Perchlorate Medium

Kinetics and Mechanism of Ruthenium(III) Chloride Catalyzed Oxidation of Cinnamyl Alcohol by Thallium(III) in Acid Perchlorate Medium

On the role of bismuth as modifier in AuPdBi catalysts: Effects on liquid-phase oxidation and hydrogenation reactions

There is much about the action of bismuth within heterogeneous catalysis that still require a deeper understanding. We observed that, when Bi was added to AuPd bimetallic nanoparticles (NPs) supported on activated carbon, Bi affected the activity and significantly alters the selectivity in two model liquid phase reactions, namely the oxidation of cinnamyl alcohol and the hydrogenation of cinnamaldehyde. A combination of transmission electron microscopy and X-ray absorption spectroscopy provided a detailed characterization of trimetallic AuPdBi systems. We propose that the introduction of bismuth on AuPd NPs results in a partial blockage of most active sites, limiting the occurrence of consecutive reactions.

Selective Oxidation of Cinnamyl Alcohol to Cinnamaldehyde over Functionalized Multi-Walled Carbon Nanotubes Supported Silver-Cobalt Nanoparticles

The selective oxidation of alcohols to aldehydes has attracted a lot of attention because of its potential use in agrochemicals, fragrances, and fine chemicals. However, due to homogenous catalysis, low yield, low selectivity, and hazardous oxidants, traditional approaches have lost their efficiency. The co-precipitation method was used to synthesize the silver-cobalt bimetallic catalyst supported on functionalized multi-walled carbon nanotubes (Ag-Co/S). Brunauer Emmet Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD) were used to characterize the catalyst. For the oxidation of cinnamyl alcohol (CA) with O2 as an oxidant, the catalyst’s selectivity and activity were investigated. The impacts of several parameters on catalyst’s selectivity and activity, such as time, temperature, solvents, catalyst dosage, and stirring speed, were comprehensively studied. The results revealed that in the presence of Ag-Co/S as a catalyst, O2 could be employed as an effective oxidant for the catalytic oxidation of cinnamyl alcohol to cinnamaldehyde (CD) with 99% selectivity and 90% conversion. In terms of cost effectiveness, catalytic activity, selectivity, and recyclability, Ag-Co/S outperforms the competition. As a result, under the green chemistry methodology, it can be utilized as an effective catalyst for the conversion of CA to CD.

Sonochemical synthesis of highly efficient Ag3PO4-Guar gum nanocomposite with photo-oxidation property under visible light irradiation

The selective oxidation of aromatic alcohols to aldehyde in an energy-efficient and environmentally benign route remains a challenge. In this study, cubical Ag3PO4-guar gum nanocomposite was synthesised by a simple ultrasound assisted co-precipitation method. The crystalline structure, optical absorption, composition and microstructure of nanocomposites were characterised by X-ray diffraction, photoluminescence, UV-Vis diffuse reflectance spectroscopy, FT-IR spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The surface modification of Ag3PO4-guar gum nanocomposite dramatically enhanced the photocatalytic oxidation activity. The results from characterisation indicated the compact structure, feasibility to control the size of nanocomposite as well as exhibited higher photocatalytic activity and stability towards oxidation of cinnamyl alcohol to cinnamaldehyde. The oxidation efficiency as high as 95% was obtained. Further analysis had revealed that the holes and O2•− species have contributed to photocatalytic oxidation. The regeneration study of the catalyst displays that it could be reused with minimal loss in activity.

Trimetallic nanotubes: A bifunctional substrate for the catalytic and spectroscopic study using Surface-enhanced Raman Spectroscopy

Surface-enhanced Raman scattering (SERS) has been used in various research fields because of high sensitivity and rapid data acquisition. When combined with catalysis in a bifunctional nanostructure, it is possible to monitor molecular transformations by providing information allowing a view of the reaction mechanism and kinetics. However, it is quite challenging to combine catalytic and SERS activities on the same material. This work aimed to produce bifunctional trimetallic nanotubes with catalytic and spectroscopic properties for catalysis and SERS monitoring of the cinnamyl alcohol oxidation reaction. The nanotubes synthesized were characterized by UV–vis, SEM, TEM, XPS, and ICP-OES. The XPS spectral analysis showed the formation of metal alloys containing Ag, Au, and Pd on the nanotubes' surface. The catalytic and spectroscopic results suggest a strong dependence on the ratio between the metals used in the nanocatalyst production for better catalytic performance and greater intensification of the Raman signal. With the SERS spectra and the results obtained by Gas chromatography, it was possible to suggest the reaction mechanism. Moreover, the stability of the catalyst was satisfactory, with 3 runs without loss of activity.