Benzyl Alcohol Research Articles

Mechanism of Electrocatalytic H2 Evolution, Carbonyl Hydrogenation, and Carbon-Carbon Coupling on Cu.

Aqueous-phase electrocatalytic hydrogenation of benzaldehyde on Cu leads not only to benzyl alcohol (the carbonyl hydrogenation product), but Cu also catalyzes carbon-carbon coupling to hydrobenzoin. In the absence of an organic substrate, H2 evolution proceeds via the Volmer-Tafel mechanism on Cu/C, with the Tafel step being rate-determining. In the presence of benzaldehyde, the catalyst surface is primarily covered with the organic substrate, while H* coverage is low. Mechanistically, the first H addition to the carbonyl O of an adsorbed benzaldehyde molecule leads to a surface-bound hydroxy intermediate. The hydroxy intermediate then undergoes a second and rate-determining H addition to its α-C to form benzyl alcohol. The H additions occur predominantly via the proton-coupled electron transfer mechanism. In a parallel reaction, the radical α-C of the hydroxy intermediate attacks the electrophilic carbonyl C of a physisorbed benzaldehyde molecule to form the C-C bond, which is rate-determining. The C-C coupling is accompanied by the protonation of the formed alkoxy radical intermediate, coupled with electron transfer from the surface of Cu, to form hydrobenzoin.

Ortho-Alkynyl Benzyl Alcohols as C6 Synthons in Regioselective Construction of Polysubstituted Naphthalenes.

A straightforward methodology for the assembly of polysubstituted naphthalenes from ortho-alkynyl benzyl alcohols, enabled by using catalytic amounts of Tf2O, has been developed. This transformation not only features transition-metal free and without using other bases and additives but also provides a new synthetic application for ortho-alkynyl benzyl alcohols, i.e., as C6 synthons for the construction of PAHs.

Highly Selective Photooxidation of Benzyl Alcohol to Benzaldehyde by Bi–Mo/g-C3N4 in Aqueous Solution

Highly Selective Photooxidation of Benzyl Alcohol to Benzaldehyde by Bi–Mo/g-C₃N₄ in Aqueous Solution

Methyl salicylate affects fruit quality and aroma compounds of cherry during cold storage

Cherries are easy to soften and rot during the period of storage. This work was performed to assess the impact of different concentrations of methyl salicylate (MeSA, 0.1 mmol·L−1, 1.0 mmol·L−1, 2.0 mmol·L−1) on fruit quality and aroma compounds of cherries (‘Meizao’ and ‘Labins’) during cold storage (0 °C). Results showed that 1.0 mmol·L−1 of MeSA had the greatest effect on decreasing the respiration rate, improving the firmness and maintaining the soluble solids content (SSC) of cherry fruits. The main volatile aroma compounds in ‘Meizao’ and ‘Labins’ cherries were benzyl alcohol, hexanal, trans-2-hexenal, benzaldehyde and 2-hexenal. Additional observations revealed that MeSA could increase the ester aroma compounds and delay the loss of alcohol, aldehyde, ketone and terpenoid aroma compounds in postharvest cherries. Therefore, MeSA could effectively improve the quality and inhibit aroma loss of cherry fruits during cold storage.

Hollow heterojunction with dual-vacancy engineering to boost photocatalytic performance for photoreduction of CO2 coupled with selective oxidation of benzyl alcohol to benzaldehyde

CO2 photoreduction into chemical fuels is hopeful and sustainable for a carbon–neutral future. Herein, a bifunctional dual-vacancy-modified hollow heterojunction photocatalyst is ingeniously designed for CO2 photoreduction to CO coupling with selective oxidation of benzyl alcohol to benzaldehyde. Synergistic catalysis effect resulted from hollow heterostructures, TiO2 with O vacancies (TiO2-x) and Zn0.3-xCd0.7S with Zn vacancies (ZCS) leads to excellent photoreduction and photoxidation performances. The optimized sample (TiO2-x/ZCS hollow sphere) exhibits highest photocatalytic activity of all the obtained samples. The yields of CO and benzaldehyde are 105 and 323.5 μmol g–1h−1, respectively. The construction of Z-scheme heterojunction realizes the spatial separation of redox reaction sites, and the dual-vacancy distributed on the heterojunction enhance the interfacial reactivity. Additionally, density functional theory calculation and in-situ technology reveal that Zn vacancy in ZCS and O vacancy in TiO2-x function as active sites for the binding and activation of *COOH and *PhCH2O-, respectively, thereby stabilizing the crucial step in the formation of intermediates such as CO and benzaldehyde. This work enhances the utilization of photogenerated carrier, and affords a new opportunity to design hollow heterojunction with dual-vacancy engineering to boost photocatalytic performance for coupling reaction system.

Evaluation of the Greenness, Whiteness, and blueness profiles of stability indicating HPLC method for determination of Denaverine hydrochloride and benzyl alcohol in pharmaceuticals

Recently, there has been important emphasis in pharmaceutical analysis on the stability of drug formulations and the development of appropriate stability-indicating studies. In this regard, a comprehensive stability-illustrating RP-HPLC approach has been established and validated for the assay of denaverine hydrochloride (DEN) and benzyl alcohol (BNZ) in Sensiblex® Injectable Solution.Different stress conditions were applied to both components, following the guidelines of the International Conference on Harmonization (ICH). Using the isocratic elution technique, DEN, BNZ, and their degradation products were effectively isolated and quantified on an Inertsil C8 column at room temperature. The mobile phase consisted of acetonitrile: water: orthophosphoric acid (80:20:0.1, by volume), and the flow speed was maintained at 0.8 mL/min. Detection was performed at 220 nm using a diode array detector, with concentration ranges of 10.00–30.00 and 5.00–15.00 μg/mL for DEN and BNZ, respectively. The total analysis time was less than five minutes, establishing this novel chromatographic method as a priority for routine quality control analysis of both drugs. The inclusion of acetonitrile was necessary for achieving adequate resolution. The environmental impact was evaluated using three approaches: Green Analytical Procedure Index (GAPI), Analytical Eco-Scale, and Analytical GREEnness metric (AGREE). Additionally, White Analytical Chemistry (WAC) was employed to evaluate the quality (R), ecological impact (G), and economic viability (B) of the developed approach.Additionally, the newly presented Blue Applicability Grade Index (BAGI) metric was also assessed. The final Eco-scale score of 85 and the AGREE score of 0.65 indicate the environmentally friendly nature of the new chromatographic method. The BAGI final score was 82.5, while the overall score of the WAC tool was 91.8, highlighting the method's practicality and utility. DEN exhibits the highest degradation (24%) in acidic conditions, whereas BNZ is particularly susceptible to oxidative degradation, with a degradation percentage of 35%. New four degradation products were formed, and the two investigated compounds were efficiently separated and analyzed in their presence. Further identification of degradation products for DEN and BNZ is strongly recommended, employing a mass spectrophotometric detector. Notably, the novel method is accurate, reliable, economical, and time-efficient. In conclusion, it can be effectively employed for routine quality control and stability assessment of DEN and BNZ in both their pure form and pharmaceutical formulations.

Photothermal Methanation of CO with Benzyl Alcohol as a Hydrogen Source Using Au–Ni Alloy Catalyst

Photothermal Methanation of CO with Benzyl Alcohol as a Hydrogen Source Using Au–Ni Alloy Catalyst

Biodegradation of DEP, DIBP, and BBP by a psychrotolerant Sphingobium yanoikuyae strain P4: Degradation potentiality and mechanism study.

Phthalic acid esters (PAEs) are human made chemicals widely used as plasticizers to enhance the flexibility of plastic products. Due to the lack of chemical bonding between phthalates and plastics, these materials can easily enter the environment. Deleterious effects caused by this chemo-pollutant have drawn the attention of the scientific community to remediate them from different ecosystem. In this context, many bacterial strains have been reported across different habitats and Sphingobium yanoikuyae strain P4 is among the few psychrotolerant bacterial species reported to biodegrade simple and complex phthalates. In the present study, biodegradation of three structurally different PAEs viz., diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), and butyl benzyl phthalate (BBP) have been investigated by the strain P4. Quantitative analyses through High-performance liquid chromatography (HPLC) revealed that the bacterium completely degraded 1g/L of DEP, DIBP, and BBP supplemented individually in minimal media pH 7.0 within 72, 54, and 120h of incubation, respectively, at 28°C and under shake culture condition (180rpm). In addition, the strain could grow in minimal media supplemented individually with up to 3g/L of DEP and 10.0g/L of DIBP and BBP at 28°C and pH 7.0. The strain also could grow in metabolites resulting from biodegradation of DEP, DIBP, and BBP, viz. n-butanol, isobutanol, butyric acid, ethanol, benzyl alcohol, benzoic acid, phthalic acid, and protocatechuic acid. Furthermore, phthalic acid and protocatechuic acid were also detected as degradation pathway metabolites of DEP and DIBP by HPLC, which gave an initial idea about the biodegradation pathway(s) of these phthalates.

Construction of a Dual-Function Mo-ZIS@Ti for Photocatalytic Benzyl Alcohol Oxidation and Hydrogen Evolution Performance.

The photocatalytic oxidation of benzyl alcohol and the simultaneous evolution of hydrogen from water are efficient dual-optimal routes. It is important to develop composite catalysts that combine redox properties and facilitate electron-hole separation and transport. Herein, the bimetallic-doped Mo-ZIS@Ti photocatalyst was designed and synthesized, and the selective oxidation of benzyl alcohol and hydrogen evolution by water splitting was realized at the same time. Under visible light irradiation, benzyl alcohol was completely converted with more than 99% selectivity for benzaldehyde, and the H2 production rate was 5.6 times higher than the initial ZIS. The exceptional catalytic performance was ascribed to utilizing Ti-MIL-125 as a precursor, wherein slowly releasing-doped Ti formed robust Ti-S bonds that quickly transfer electrons and reduce sites. Meanwhile, doping Mo effectively captures photogenerated holes and acts as active sites for oxidation reactions. Both experimental characterization and work function calculations demonstrate that the bimetallic synergism effectively modulates the electronic structure of ZIS, promotes the directional separation of electrons and holes, and significantly improves the photoactivity and stability of ZIS. This work contributes a route to obtain benzaldehyde and green hydrogen at the same time and also gives new insights for the construction and mechanism study of bimetallic-doping catalysts.

Unraveling defect chemistry in doped-ceria catalyst for oxidative coupling of lignin-based aniline and benzyl alcohol

The defect chemistry of doped-ceria is vital but tangled for sustainable conversion of biomass resources. In this work, a group of Zr-doped CeO2 solid solutions were prepared and the defect chemistry in CeZrxOy (0.02 ≤ x ≤ 5) catalyst was elucidated over the oxidative coupling of lignin-based aniline and benzyl alcohol. Varying the Zr molar fraction enabled to successfully adjust the defect sites of catalysts and further influence their catalytic performances. In addition, the optimal CeZr1Oy catalyst exhibited a flexible temperature adaptability, wide substrate scope and superior reusability. Various characterizations, kinetic investigations, controlled experiments, DFT calculations and in situ DRIFT-IR technique were used to unravel the roles of Ce3+ and oxygen defects and the reaction mechanism. It was disclosed that Zr-doped defects can obviously increase surface Ce3+ cations, oxygen species (peroxide and superoxide anions) and oxygen vacancies. These coordinatively unsaturated sites were shown to play critical roles in absorbing and activating substrates hence can accelerate the formation rate of bio-based imines.

Enhancing Photocatalytic Activity, Stability, and Separability of TiO2 through Synthesis of Fe3O4@Fibroin‐TiO2 Composite

AbstractThis report uses a low‐cost and straightforward technique to synthesize a highly active, magnetically separable, and optically active nano‐biocomposite. The nanocomposite was created by combining Fibroin, TiO2, and Fe3O4. The analyses confirmed the formation of a core‐shell structure of Fibroin and Fe3O4, which was then combined with titanium dioxide nanoparticles. The incorporation of nanoparticles reduced the band gap of the system from 3.2 eV in bare titanium oxide to 1.8 eV. This enhancement improved its light absorption and charge generation. Additionally, the nano‐biocomposite showed improved chemical stability and photocatalytic activity when compared to bare TiO2 in the oxidation of benzyl alcohol under visible light (With 99 % yield and over 99 % selectivity). These results suggest that our nano‐biocomposite is a promising catalyst for photocatalytic applications under visible light.

Steering benzyl alcohol electrooxidation coupled with hydrogen evolution via hetero‐interface construction

AbstractIt is still a challenge to develop electrocatalyst for the efficient adsorption and conversion of organic molecule in aqueous media. Herein, a hetero‐interface structure based on CuO@Ni(OH)2 is rationally designed to enhance the performance of benzyl alcohol oxidation to benzoic acid. A high Faradaic efficiency of 99% and the yield of 3.09 mmol cm−2 h−1 are achieved at 1.70 V versus reversible hydrogen electrode, outperforming the previously reported electrocatalysts. Furthermore, a membrane‐free flow electrolyzer was assembled based on CuO@Ni(OH)2 hetero‐interface, exhibiting a much high yielding of benzoic acid (6.73 mmol cm−2 h−1) and hydrogen (0.35 L cm−2 h−1) with excellent stability. Both experimental data and density functional theory calculations verify that the electron is tend to accumulate at the hetero‐interface, thus accelerating the adsorption of reactant and intermediate and reducing the energy barrier of the conversion of benzyl alcohol to benzoic acid.

Significant augmentation of hydrogen and benzaldehyde production through mediator-free in-situ synthesis of CuNi/CN photocatalysts for benzyl alcohol splitting

Amidst growing concerns surrounding global warming and energy scarcity, there is an urgent demand for more efficient and environmentally friendly methods of hydrogen production. In response, we introduce a novel mediator-free in-situ approach for synthesizing CuNi/CN composite photocatalysts. This method entails the synthesis of copper and nickel complexes to fabricate bimetallic Cu and Ni nanoparticles on carbon nitride (CN). These catalysts are deployed for the photocatalytic dehydrogenation of benzyl alcohol, resulting in the generation of hydrogen and benzaldehyde. The CuNi bimetal-loaded CN structure provides ample active sites and demonstrates a low hydrogen reduction overpotential, thereby enhancing both charge separation and surface hydrogen reduction processes. In comparison to pure CN, the composite photocatalyst exhibits significantly improved photocatalytic activity. Notably, the composite 2 % Cu1Ni1/CN photocatalyst achieves a record-high hydrogen production rate of about 80 μmol g-1h−1, representing an impressive increase of approximately 533 times compared to pristine CN. Moreover, the catalyst offers cost-effectiveness, ease of preparation, and reusability, ensuring stable hydrogen production efficiency over multiple cycles. This precious metal-free composite photocatalyst not only facilitates the synthesis of valuable compounds but also promotes sustainable advancements in efficient hydrogen energy generation.

Palladium-iron bimetallic-catalyzed cross-coupling reaction of alcohols and nitroarenes using a hydrogen-transfer redox system

Abstract A Pd/Fe bimetallic catalyst in the presence of the Xantphos ligand promoted the cross-coupling reaction of alcohols and nitroarenes via a hydrogen-transfer redox system. The consecutive formation of aldimines from benzyl alcohols and nitroarenes proceeded in three steps in a single manipulation: oxidation of alcohols, reduction of nitroarenes, and dehydrative condensation of aldehydes and aminoarenes.

Towards lignin-based polyurethanes: a computational study of the influence of the reactants structure on the formation of urethanes in the presence of tin(II) dicarboxylate as a catalyst

An in-depth computational investigation of the tin-catalysed reaction of an alcohol with an isocyanate forming a urethane has been performed to elucidate the influence of the reactants, most importantly the type of alcohol or phenol, on its kinetics. The model alcohols were chosen based on those alcohol moieties present in lignin and comprised aliphatic, aromatic and benzylic alcohols, and reactions with both aliphatic and aromatic isocyanates were studied by modelling the rate-determining step of the urethane formation based on the mechanism proposed by Devendra et al. The results show that N-coordination is both kinetically and thermodynamically favoured for all reactions under consideration. Aliphatic alcohols react more readily than phenols with an aliphatic isocyanate, while benzylic alcohols react similarly to a bulky aliphatic alcohol. In the case of phenols, the kinetics are not influenced by the presence and/or number of ortho‑methoxy groups, but these will slightly alter the thermodynamics of the reaction. Aliphatic alcohols show slightly improved kinetics when reacting with an aromatic isocyanate, whereas phenols show no such preference. The reactions with the aliphatic isocyanate were also modelled in DMSO, but no significant changes in reaction kinetics were observed.

Preparation and Physicochemical Properties of a Thermosensitive Hydrogel-based Lipopeptide Biosurfactant

Background: Temperature-sensitive (thermo-sensitive) formulations are a novel drug delivery dosage form that shows bio-inspired behavior in various applications. The structure and properties of a thermosensitive polymer are critical in designing an intelligent biometric polymer that contains lipopeptide biosurfactants. Objectives: In this study, thermo-sensitive hydrogels with lipopeptide biosurfactants as a potential wound dressing dosage form were formulated and examined regarding physicochemical properties. Methods: The lipopeptide biosurfactants were isolated from the Acinetobacter junni B6 bacterial strain and loaded on a formulation of poloxamer 407® and carboxymethyl cellulose as a gelling agent. Numerous experiments were carried out to evaluate the physicochemical properties of these formulations, such as the stability, spreadability, release profile, and kinetic. Results: The formulation (Poloxamer 407® (19% w/v), carboxymethyl cellulose (2% w/v), lipopeptide biosurfactants (5mg/mL), benzyl alcohol (1% v/v), and 0.1mL polyethylene glycol 400) was select as the optimum formulation. The selected formulation released 26.9% of the lipopeptide biosurfactants with anomalous transport kinetics after 10 hours. Conclusions: The results showed that a thermo-sensitive formulation could help achieve a sustained release of lipopeptide biosurfactants and potentially be used as a dressing formulation for wounds in future studies.

Crafting in situ boron and selenium-doped carbon nitride nanosheets for turbocharged benzaldehyde to benzyl alcohol under solar spectrum

This research focuses on the fabrication and application of in situ boron and selenium-doped carbon nitride nanosheets as effective photocatalysts using sun spectrum irradiation to convert turbocharged benzaldehyde to benzyl alcohol. To optimize the doping method for enhanced activity, the effect of changing dopant concentrations on catalytic efficiency was thoroughly investigated. Furthermore, a through analysis of the reactive species involved in the conversion process helped to clarify the photocatalytic process. Based on charge transfer and low recombination, the results indicate that boron and selenium dopants work synergistically to improve catalytic efficiency. This research helps to improve the development of new photocatalytic materials for the sustainable and ecologically friendly transformation of organic molecules under solar spectrum irradiation. The regeneration of NADH using B,Se-CN photocatalyst demonstrates very good efficiency. It also demonstrated the high conversion efficiency of benzaldehyde to benzyl alcohol. This study emphasizes the possible use of B,Se-CN composite in the area of photoinduced conversion-based organic transformation. The knowledge gathered from this research opens up new avenues for the development and enhancement of effective photocatalysts that might be used in a range of solar-powered organic transformation processes.

Fabricating a Structured Single‐Atom Catalyst via High‐Resolution Photopolymerization 3D Printing

AbstractThis study introduces a novel solution to the design of structured catalysts, integrating single‐piece 3D printing with single‐atom catalysis. Structured catalysts are widely employed in industrial processes, as they provide optimal mass and heat transfer, leading to a more efficient use of catalytic materials. They are conventionally prepared using ceramic or metallic bodies, which are then washcoated and impregnated with catalytically active layers. However, this approach may lead to adhesion issues of the latter. By employing photopolymerization printing, a stable and active single‐atom catalyst is directly shaped into a stand‐alone, single‐piece structured material. The battery of characterization methods employed in the present study confirms the uniform distribution of catalytically active species and the structural integrity of the material. Computational fluid dynamics simulations are applied to demonstrate enhanced momentum transfer and light distribution within the structured body. The materials are finally evaluated in the continuous‐flow photocatalytic oxidation of benzyl alcohol to benzaldehyde, a relevant reaction to prepare biomass‐derived building blocks. The innovative approach reported herein to manufacture a structured single‐atom catalyst circumvents the complexities of traditional synthetic methods, offering scalability and efficiency improvements, and highlights the transformative role of 3D printing in catalysis engineering to revolutionize catalysts’ design.

Extraordinary synergy on 3D hierarchical porous Co-Cu nanocomposite for catalytic elimination of VOCs at low temperature and high space velocity

It is still a challenge to develop hierarchically nanostructured catalysts with simple approaches to enhance the low-temperature catalytic activity. Herein, a set of mesoporous Co-Cu binary metal oxides with different morphologies were successfully prepared via a facile ammonium bicarbonate precipitation method without any templates or surfactants, which were further applied for catalytic removal of carcinogenic toluene. Among the catalysts with different ratios, the CoCu0.2 composite oxide presented the best performance, where the temperature required for 90% conversion of toluene was only 237°C at the high weight hour space velocity (WHSV) of 240,000 mL/(gcat·hr). Meanwhile, compared to the related Co-Cu composite oxides prepared by using different precipitants (NaOH and H2C2O4), the NH4HCO3-derived CoCu0.2 sample exhibited better catalytic efficiency in toluene oxidation, while the T90 were 22 and 28°C lower than those samples prepared by NaOH and H2C2O4 routes, respectively. Based on various characterizations, it could be deduced that the excellent performance was related to the small crystal size (6.7 nm), large specific surface area (77.0 m2/g), hollow hierarchical nanostructure with abundant high valence Co ions and adsorbed oxygen species. In situ DRIFTS further revealed that the possible reaction pathway for the toluene oxidation over CoCu0.2 catalyst followed the route of absorbed toluene → benzyl alcohol → benzaldehyde → benzoic acid → carbonate → CO2 and H2O. In addition, CoCu0.2 sample could keep stable with long-time operation and occur little inactivation under humid condition (5 vol.% water), which revealed that the NH4HCO3-derived CoCu0.2 nanocatalyst possessed great potential in industrial applications for VOCs abatement.

Selective hydrodeoxygenation of 5-hydromethylfurfural to 2,5-dimethylfuran over PtFe/C catalyst

2,5-dimethylfuran (DMF), a promising biomass-derived fuel, is synthesized via the hydrodeoxygenation of 5-hydroxymethylfurfural (HMF). This study focuses on the inherent activity of a 5Pt5Fe/C catalyst for HMF hydrodeoxygenation to DMF. The catalyst exhibited exceptional performance, achieving a remarkable DMF yield of 99.6 %. It displayed specific selectivity for C = O bond hydrogenation and CO bond cleavage in diverse substrates, producing high yield of 2-methylfuran from furfural and furfury alcohol, and high yield of toluene from benzaldehyde, benzyl alcohol. In-depth characterizations unveiled valuable insights into the 5Pt5Fe/C catalyst's properties, emphasizing a harmonious balance between metal and acid sites due to the interactive synergy between Pt and Fe species, enhancing hydrodeoxygenation activity. Additionally, the catalyst demonstrated satisfactory stability, maintaining a commendable DMF yield over five reaction cycles despite observed changes.