Oxidation Of Alcohols Research Articles

Novel Inorganic‐Organic Dual‐Photosensitizing Dinuclear‐Metal Self‐Assembly System for Efficient Artificial Photosynthesis without Sacrificial Electron Donors

AbstractOwing to the unique synergistic effect, dinuclear‐metal‐molecule‐catalysts (DMCs) show excellent performance in catalytic fields. However, for overall photocatalytic CO2 reaction (CO2RR), it is still a challenge to construct well‐matched photosensitizer (PS) components for DMCs‐based photocatalysts. Inorganic‐quantum‐dot PS possesses capacities of multiple exciton generation and catalyzing water oxidation but is incompatible with DMCs. In contrast, organic PS can be covalently linked with DMCs but inescapable of using sacrificial electron donors. For overall photocatalytic CO2RR, organic–inorganic dual‐photosensitizing system might be a promising candidate. Herein, we employed covalent‐linking and electrostatic‐driven approaches to construct the self‐assembly of pyrene‐sensitized Co2L DMCs (Py‐Co2L) and perovskite (PVK) quantum dots, i.e., PVK@[Py‐Co2L]. Using H2O as an electron donor, PVK@[Py‐Co2L] realized 105.24 μmol ⋅ g−1⋅h−1 CO yield in photocatalytic CO2RR, much higher than PVK (15.44 μmol ⋅ g−1⋅h−1) and PVK@Co2L (32.30 μmol ⋅ g−1 ⋅ h−1), ascribing to the efficient photogenerated charge separation and transfer. The experimental results and theoretical investigations demonstrated that the pyrene linked on Co2L boosted the electron delivery from PVK to DMCs. Besides, this strategy could also be extended to the photocatalytic H2 evolution coupled with alcohol oxidation. As a proof‐of‐concept, our work lightens the integration of DMCs, organic and inorganic PS components, promoting the development of photocatalysis without sacrificial electron donors.

Bases Tuning Selective Aerobic Oxidation of Benzyl Alcohol to Benzaldehyde Catalyzed by Cu2+/TEMPO

Bases Tuning Selective Aerobic Oxidation of Benzyl Alcohol to Benzaldehyde Catalyzed by Cu2+/TEMPO

Preparation and Catalytic Properties of Gold Single-Atom and Cluster Catalysts Utilizing Nanoparticulate Mg-Al Layered Double Hydroxides.

Au single atoms and clusters were stabilized on Mg-Al layered double hydroxide nanoparticles (LDH NPs), and the obtained Au@LDH NPs were supported on SiO2 and CeO2. After hydrogen reduction, Au single atoms were found together with Au clusters on LDH/SiO2. In contrast to Au single-atom catalysts which are deposited in metal vacancies of oxide supports, the LDH NPs stabilize very small Au species despite the absence of metal vacancies. The obtained Au(0)@LDH/SiO2 catalyzed aerobic oxidation of alcohols, and Au single atoms maintained after the reaction. Given that only Au NPs were observed on bulk LDH, the abundant surface OH group of LDH NPs would contribute to stabilize Au, resulting in higher activity than Au/LDH-bulk. After calcination to transform LDH to mixed metal oxide (MMO), the obtained Au(0)@MMO/SiO2 also exhibited high catalytic activity. Moreover, Au(0)@LDH/CeO2 exhibited higher activity and excellent selectivity for hydrogenation of 4-nitrostyrene to 4-aminostyrene than conventional Au catalysts such as Au/CeO2 and Au/TiO2. We demonstrated that Au size can be minimized using LDH NPs, exhibiting high catalytic performance. The basic surface OH groups of LDH would be also beneficial for deprotonation of alcohols and heterolytic dissociation of H2 in the catalytic reactions.

In Situ X-ray and Infrared Spectroscopic Studies of Electrochemical Systems

Abstract Despite a wealth of data and intense research, the phenomena occurring during electrocatalysis are still a major obstacle in many chemical processes. Molecular analysis of the electrode/electrolyte interface is needed to correctly describe the reaction through identifying the species involved, their interaction with the environment and kinetics in situ, i.e. while the reaction is taking place. That can be done by coupling the electrochemical system with complementary non-electrochemical techniques. In addition, in situ x-ray spectroscopic techniques analyze the electrode itself, providing the information on the changes in the catalyst during the reaction. The synergy of the traditional electrochemical techniques with the complementary spectroscopic methodologies offer understanding of the electrode/electrolyte interface above and beyond traditional experimental mainframe. Here we demonstrate how in situ X-ray absorption spectroscopy, in situ infrared reflection/absorption spectroscopy, and traditional voltammetric studies can reveal electrochemical processes during oxidation of ethanol, enhance the structure and selectivity of the catalyst to complete oxidation pathway, and provide understanding of the parameters that enhance its oxidation for future designing catalysts for alcohol oxidation fuel cells.

Aerobic Oxidation of Alcohols and Olefins Using Ru NPs Decorated on Functionalized PNIPAM Grafted Magnetic Nanoparticles

ABSTRACTA thermo‐responsive ruthenium catalyst was produced by immobilizing poly(N‐isopropyl acrylamide) on the silica surface coated iron oxide nanoparticles (Fe3O4@Si). After being exposed to ethylenediamine, the amino‐modified support (Fe3O4@Si‐PNIPAM‐NH2) was produced, and Fe3O4@Si‐PNIPAM‐NH2‐EDTA was made in the ensuing reaction with EDTA (ethylenediaminetetraacetic acid). Ru NPs were introduced to the modified magnetic support to create a well‐organized heterogeneous catalytic system with several advantages, such as enabling catalyst recycling and simple separation. This new catalyst was characterized by means of various techniques, including TGA, ICP, FT‐IR, DLS, TEM, SEM, EDX, VSM, XRD, CHN, and XPS. In the presence of H2O2 or air alone, this catalyst showed a significant effect in the oxidation of various alcohols to the corresponding aldehydes or ketones. Furthermore, the catalyst exhibited outstanding capacity in the aerobic oxidation of olefines to the carbonyl or oxirane counterparts. A main aspect of this catalytic system is the reusability of the catalyst at least eight times in consecutive runs without causing any discernible loss of activity, structural change, or leaching.

A New CuI/Oxalamide Catalytic System for the Large‐Scale Aerobic Oxidation of Alcohols

AbstractSince the report of oxamide ligands, they have been widely used for the efficient construction of various types of C−X (such as C, N, O and S) bonds. To evaluate whether the easily tunable electronic properties and unique coordination modes of oxamide ligands can also shine in the field of oxidation, we initiated a study on oxamide ligand/copper/air oxidation and applied it to the oxidation of alcohols to assess its practicality and potential applications. The practicality of this strategy was further verified through scale‐up reactions on a 100 mmol scale and gram‐scale derivatization of pharmaceutical molecules.

Nanocellulose‐reinforced, anti‐freezing, highly conductive ionic organic hydrogels for flexible electronic devices

AbstractCurrently, flexible electronic devices based on ionic conductive hydrogels are receiving widespread attention in the field of human health detection. In this paper, a facile one‐pot method is proposed for the preparation of ionic organic hydrogels, in which polyvinyl alcohol (PVA), cellulose nanofiber (CNF), and graphene oxide (GO) are dissolved in dimethyl sulfoxide‐water (DMSO/H2O), and the organic hydrogel is obtained by a freezing–thawing process. The ionic organic hydrogel with excellent properties is then prepared by soaking the hydrogel in a calcium chloride (CaCl2) solution using a salting‐out strategy. The ionic organic hydrogel possesses good tensile (283%) and strength (0.3 MPa), super electrical conductivity (7.72 S/m), and high strain sensitivity [gauge factor (GF) up to 5.22]. Meanwhile, it has excellent anti‐freezing and moisturizing properties. In addition, the ionic organic hydrogels can be used in flexible strain sensors and triboelectric nanogenerators to realize real‐time monitoring of human motion, traceless writing, and energy conversion. It is foreseen that the prepared ionic organic hydrogels provide a feasible method for realizing the long‐term use of wearable electronic devices in extreme environments and daily life.

Efficient and selective oxidation of alcohols and hydrocarbons catalyzed by oxovanadium(IV) unsymmetrical salophen complex supported on silica-coated CoFe2O4 magnetic nanoparticles

Efficient and selective oxidation of alcohols and hydrocarbons catalyzed by oxovanadium(IV) unsymmetrical salophen complex supported on silica-coated CoFe2O4 magnetic nanoparticles

Platinum and CeO2−x Occlusion Electrodeposition at Unsupported Vulcan XC-72R for Methanol and Ethanol Oxidation Reactions in Alkaline Media

Platinum was electrodeposited in a slurry solution of CeO2 and Vulcan XC-72R to produce Pt/CeO2−x/Vulcan XC-72R catalysts by using the Rotating Disk Slurry Electrodeposition (RoDSE) Technique. The activity of the catalysts was measured towards methanol and ethanol oxidation reactions in alkaline conditions by cyclic voltammetry and chronoamperometry. The electrochemical results were compared to those obtained on commercial catalysts. Pt/CeO2−x/Vulcan XC-72R (with ∼ 26 wt% Pt) catalyst was the most active for both alcohol oxidation reactions when compared to commercial 40 wt.% and 20% /Vulcan XC-72R (ETEK) catalysts. The mass activity increases 2.0x and 2.4x for methanol and ethanol oxidation reactions when compare with 40 and 20 Pt wt. % commercial catalysts, respectively. The Pt/CeO2−x/Vulcan XC-72R catalysts contained Pt nanoparticles growth within the cerium oxide through an occlusion electrodeposition method. These effects were systematically investigated using X-ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HR-TEM), and X-ray Photoelectron Spectroscopy (XPS).

Recent Progress in Situ Application of H2O2 Produced via Catalytic Synthesis.

Industrial production of H2O2 requires lots of energy and causes environmental pollution. Moreover, in subsequent applications, much economic loss could be produced during the transportation process of H2O2 and its dilution process. Therefore, it is highly desirable for in situ application of H2O2. In recent years, catalytic synthesis of H2O2, e. g., direct catalytic synthesis, electrocatalytic synthesis, and photocatalytic synthesis, has attracted more and more attention because the continuous and low-concentration H2O2 produced by catalytic synthesis can be directly used for the oxidation of organic compounds, effectively avoiding the shortcomings of the current industrial route. Here, we briefly reviewed the latest processes for the catalytic production of H2O2 via various routes. On this basis, we summarized and discussed the in situ application of H2O2 in typical organic conversion reactions, including the ammoximation of ketones, the oxidation of alcohols, the oxidation of C-H bonds, and the oxidation of olefins. Some in situ coupling reactions have shown excellent performance with high conversion and selectivity, and the economic cost has been significantly reduced. Finally, the shortcomings of the in situ utilization of H2O2 in coupling reactions were analyzed, and some strategies for promoting the efficiency of the H2O2 application in organic synthesis were proposed.

Right iliac deep vein thrombosis and pulmonary embolism associated with recreational nitrous oxide: a case report

BackgroundThe recreational use of nitrous oxide is becoming increasingly common among teenagers and young adults. Since 2018, the use of nitrous oxide has increased exponentially and has become a public health problem.Case presentationA 23-year-old patient was referred to accident and emergency (A&E) by his general practitioner for deterioration in general condition, vomiting, diarrhea and febrile headache at 39 °C.He reported that he had been partying for a month and consuming alcohol, cannabis and nitrous oxide. Three days before the consultation, he reported increased abdominal pain in the right iliac fossa. His homocysteine concentration was 51.9 μmol/L, and his plasma methyl malonate concentration increased to 4.45 μmol/L. A thoracic and abdominal CT scan revealed right iliac venous thrombosis associated with bilateral pulmonary embolism.ConclusionNitrous oxide inhibits the activity of methionine synthetase. We therefore observed an increase in plasma homocysteine and 5-methyl-THF. The increase in homocysteine could be responsible for the pro-thrombotic activity resulting from nitrous oxide intoxication. At present, no threshold or duration of exposure has been identified as being particularly likely to cause complications. It is likely that other factors coexist, such as coagulation disorders and polymorphisms of the MHTFR gene, which can lead to hyperhomocysteinaemia, cannabis consumption, inflammatory conditions and others. Treatment is based on vitamin B12 supplementation and curative anticoagulation. Some authors also recommend folate supplementation.Consumption of nitrous oxide could be associated with arterial and venous thromboembolic disease.

Selective Oxidation of Alcohols to Carbonyls Under Decatungstate-Mediated Photoelectrochemical Conditions.

The oxidation of alcohols to the corresponding carbonyl derivatives has been realized under photoelectrochemical conditions in the presence of tetrabutylammonium decatungstate (TBADT) as the homogeneous photocatalyst. The protocol can be applied to both primary and secondary, benzylic and aliphatic alcohols. The desired products are obtained selectively, skipping the need for purposely added chemical oxidants. An in-depth study of photoelectrochemical conditions revealed that the protocol works best under amperostatic conditions in an undivided electrochemical cell irradiated with a 390 nm LED lamp. The comparison with analogous electrochemical and chemical oxidant-promoted photocatalytic transformations demonstrates the superior efficiency and selectivity of the hereby reported photoelectrochemical conditions.

Photocatalyst Design Principles for Photocatalytic Hydrogen Production and Benzyl Alcohol Oxidation with CdS Nanosheets

Photocatalyst Design Principles for Photocatalytic Hydrogen Production and Benzyl Alcohol Oxidation with CdS Nanosheets

Deciphering the mass transfer and diffusion behavior in the oxidation of fatty alcohols to fatty acids over Pt/MCM-41

Selective oxidation of long-chain fatty alcohols into acids is an important value-added reaction. However, exploring the basic catalytic steps over Pt-based catalysts throughout the entire oxidation process is still ambiguous. In this work, we systematically investigated the synergistic mechanisms of adsorption, reaction, and diffusion over Pt/MCM-41 for normal/isomeric alcohols oxidation into acids via molecular dynamics, in-situ characterization, and experiments. Specifically, diffusion coefficients decrease with the increase of the molecular weight of normal molecules due to the increased van der Waals forces, while isomeric alcohols exhibit more complex patterns originated from the steric hindrance between Pt particles and mesopores. To quantitatively describe this pattern, a cluster size descriptor of dPt0.75×dPore0.25 was defined. Notably, 2-ethylhexanol exhibits the best self-diffusion coefficients at the descriptor value of 3.14. Correspondingly, the oxidation of 2-ethylhexanol to 2-ethylhexanoic acid displays highest reaction conversion (68.67 %) and selectivity (65.59 %).

Oxidation of alcohols to carbonyl compounds with H2O2 in water catalyzed by polyoxometalate-based hyper-crosslinked ionic polymer

The oxidation reaction involving hydrogen peroxide (H2O2) in water is of great attraction in fundamental research and industrial application, but there is still a long way to go. Herein, a new hybrid catalyst PW@Py-HIP was successfully synthesized by immobilization of phosphotungstic anions onto/into the pyridinium-based hyper-crosslinked ionic polymer using a post-synthetic strategy. This facile synthetic method afforded heterogeneous catalyst with a large specific surface area of 428.7 m2·g−1 and stable polymeric skeleton. The amphiphilic PW@Py-HIP exhibited remarkable catalytic activity and quantitative selectivity for the oxidation of alcohols into carbonyl compounds with H2O2 in water. The turnover frequency (TOF) and turnover number (TON) values reached 1088.9 h−1 and 4083.3, respectively. Owing to its good heterogeneous nature, PW@Py-HIP can be recycled for six times without significant loss of activity. The developed catalytic system confirmed to be beneficial toward the synthesis of related carbonyl compounds from various alcohols with appreciable conversions.

Selective oxidation of benzyl alcohol to benzaldehyde using sustainable catalysts: An overview

Selective oxidation of benzyl alcohol to benzaldehyde using sustainable catalysts: An overview

Constructing Organic-Inorganic Woven Hybrid Membrane for Highly-Selective Catalytic Conversion of Lignin-based Phenolic Molecule to Value-added Products

Addressing the global need for sustainable chemical processes, this study introduces an innovative Woven Hybrid Membrane (WHM) specifically designed for the efficient oxidation of vanillyl alcohol (VAA) to vanillin (VLN). This transformation is crucial for converting lignocellulosic biomass into valuable chemical products, aligning with sustainable development goals. Utilizing a novel catalytic system that combines 2,2,6,6-tetramethylpiperidine 1-oxyl (TMP) and copper on a unique mesh-like structure, the WHM enhances both the economic and environmental viability of the process. This design not only overcomes the limitations of powdered catalysts, which are challenging to recover and reuse, but also promotes high catalytic efficiency and selectivity. By employing oxygen as the oxidant, our system maintains near 100% selectivity for VLN, demonstrating high conversion rates across multiple cycles without significant degradation in performance. Advanced analytical techniques, including electrochemical analysis and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), were used to explore the catalyst’s functionality and the reaction mechanism. The results confirm the stability and effectiveness of the WHM, showcasing its potential as a reusable, highly efficient, and environmentally friendly catalyst. This research represents a significant step forward in the field of sustainable industrial chemistry, offering a robust solution for the bio-refinery industry's push towards greener processes.

Silica coated N-doped carbon modified with ruthenium nanoparticles: An effective waste derived carbon nanocatalyst in oxidation reactions and also its evaluation by DFT and anti-bacterial studies

This report presents the development of an inexpensive mesoporous nanocatalyst i.e. silica coated N-doped carbon modified with ruthenium nanoparticles (Ru/RuO2@NSAC). The carbon and nanosilica components were derived from waste materials namely waste tea extract and rice husk respectively highlighting the sustainable approach to the synthesis process. The nanocatalyst was thoroughly characterized using various advanced techniques such as Fourier transform infrared spectroscopy (FTIR), Powder X-ray diffraction (P-XRD), Field emission gun-scanning electron microscopy (FEG-SEM), Energy dispersive X-ray analysis (EDX), High resolution-transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray resonance fluorescence (XRF) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). These characterizations provided comprehensive insights into the structural features of the nanocatalyst. XPS analysis confirmed the presence of both metallic ruthenium and Ru (IV) on the nanocatalytic support. The particle size of Ru/RuO2@NSAC was determined using Scherrer's equation and came out to be 21.37 nm. This nanocatalyst demonstrated remarkable performance as a robust heterogeneous catalyst for the oxidation of alkylarenes and alcohols to their corresponding carbonyl compounds. It exhibited excellent recyclability, maintaining its activity for up to five consecutive runs. Post-recycling, the catalyst was again characterized by P-XRD and FEG-SEM to ensure its structural integrity. Additionally, the antibacterial activity of Ru/RuO2@NSAC was evaluated against both Gram-positive and Gram-negative bacteria. A density functional theory study was also conducted to support the experimental findings, providing a theoretical basis for the observed catalytic behavior.

Modulating the local electron density at built-in interface iron single sites in Fe-CN/MoO3 heterostructure for enhanced CO2 reduction to CH4 and Photo-Fenton reaction

The catalytic efficiency of heterogeneous photocatalytic CO2 reduction and photo-Fenton H2O2 activationisclosely related to the local electron density of reaction center atoms. However, electron-hole recombination from random charge transfer significantly restricts the targeted electron delivery to the active center. Herein, Fe-C3N4/MoO3 heterojunction with interfacial coordination of atomically dispersed Fe-N4 sites with the O interface of MoO3 was synthesized by simple hydrothermal method. Based on the experimental results and density functional theory calculation (DFT), the heterojunction structure fosters accelerated interfacial electron transfer due to directional interfacial electric field (IEF) between Fe-CN and MoO heterogeneous interfaces, and the interfacial bond between Fe-N4 sites and O at the built-in interface regulates the local electron density of Fe-N4 active center. DFT further reveals that the interfacial electron flow and concentrated electron density at Fe-N4 sites result from the coordination between Fe-N4 and MoO3 interfaces. This directs electron flow towards the Fe center, significantly enhancing CO2 adsorption and H2O2 conversion efficiency. PDOS analysis shows that the dyz and dz2 orbitals of the isolated Fe atom in Fe-CN overlap with the pz orbital of the O atom in MoO3, playing a pivotal role in CO2 adsorption. Consequently, the Fe-CN/MoO3 heterojunction demonstrated highly efficient photocatalytic CO2 reduction to CH4, coupled with benzyl alcohol oxidation and photo-Fenton tetracycline degradation. These findings offer a promising multifunctional catalyst strategy for the development of energy conversion and environmental remediation.

Coupling Photocatalytic Hydrogen Production with Key Oxidation Reactions.

Hydrogen represents a clean and sustainable energy source with wide applications in fuel cells and hydrogen energy storage systems. Photocatalytic strategies emerge as a green and promising solution for hydrogen production, which still reveals several critical challenges in enhancing the efficiency and stability and improving the whole value. This review systematically elaborates on various coupling approaches for photocatalytic hydrogen production, aiming to improve both efficiency and value through different oxidation half-reactions. Firstly, the fundamental mechanism is discussed for photocatalytic hydrogen production. Then, the advances, challenges, and opportunities are expanded for the coupling of photocatalytic hydrogen production, which focuses on the integration of value-added reactions including O2 production, H2O2 production, biomass conversion, alcohol oxidation, and pollutants treatment. Finally, the challenges and outlook of photocatalytic H2 production technology are analyzed from the aspects of coupling hydrogen production value, photocatalyst design and reaction system construction. This work presents a holistic view of the field, emphasizing the synergistic benefits of coupled reactions and their practical application potential, rather than focusing on catalysts or single reaction systems. This review provides valuable references for the development and application of photocatalytic hydrogen production in energy conversion and environmental conservation through sustainable, eco-friendly and economic pathways.