Showing papers on "Benzaldehyde published in 2020"
TL;DR: Peroxymonosulfate (PMS) is a cheap, stable, and soluble solid oxidant, holding promise as mentioned in this paper, and it is used in the selective oxidation of benzyl alcohol into benzaldehyde (BzH).
Abstract: Selective oxidation of benzyl alcohol (BzOH) into benzaldehyde (BzH) is very important in synthetic chemistry. Peroxymonosulfate (PMS) is a cheap, stable, and soluble solid oxidant, holding promise...
149 citations
TL;DR: In this work, the combination of in situ DRIFTS and PTR-TOF-MS provided a promising approach for further understanding of the mechanism of VOCs elimination.
112 citations
TL;DR: In this paper, a holey lamellar high entropy oxide (HEO) Co0.2 Ni 0.2 Cu 0.5 Mg 0.6 Zn 0.4 O 0.1 O 0.
Abstract: The development of noble-metal-free heterogeneous catalysts is promising for selective oxidation of aromatic alcohols; however, the relatively low conversion of non-noble metal catalysts under solvent-free atmospheric conditions hinders their industrial application. Now, a holey lamellar high entropy oxide (HEO) Co0.2 Ni0.2 Cu0.2 Mg0.2 Zn0.2 O material with mesoporous structure is prepared by an anchoring and merging process. The HEO has ultra-high catalytic activity for the solvent-free aerobic oxidation of benzyl alcohol. Up to 98 % conversion can be achieved in only 2 h, to our knowledge, the highest conversion of benzyl alcohol by oxidation to date. By regulating the catalytic reaction parameters, benzoic acid or benzaldehyde can be selectively optimized as the main product. Analytical characterizations and calculations provide a deeper insight into the catalysis mechanism, revealing abundant oxygen vacancies and holey lamellar framework contribute to the ultra-high catalytic activity.
110 citations
TL;DR: Commercial TiO2 supported 0.20 wt% Pt catalyst is obtained via the molten salt method, and both Pt nanoparticles and single atom Pt sites are observed, and likely toluene combustion reaction pathway is provided.
82 citations
TL;DR: Results indicate that benzoic acid and benzaldehyde are the main accumulation because of their high reaction energy, and a possible reaction mechanism is proposed for toluene oxidation, deactivation, and regeneration of catalysts, which has a significant value for guiding the practical applications.
Abstract: This work presents a new strategy for industrial flue gas purification with TiO2-based photocatalysis technology, which could be achieved by a novel dual-stage circulating photocatalytic reactor. A lab-scale fixed bed reactor is utilized to investigate the performance of photocatalytic toluene degradation and inactive catalyst regeneration by thermal/UV treatment. The relationships between operational conditions and toluene oxidation are surveyed and discussed in detail. The results show that the intermediates could be further removed and decomposed by introducing UV radiation, compared with heat treatment alone. To reveal the photocatalytic mechanism and identify the accumulated intermediates over anatase TiO2, the adsorbed toluene and aromatic intermediates are identified by XPS, in situ DRIFTS, and on-line MS. The aromatic ring and other covalent bonds (C═O, C-O, and O-H) are detected during photocatalytic oxidation. The reaction pathway involving hydrogen abstraction is referred as the dominant pathway for toluene degradation, and ring opening via ·OH radicals is crucial to make aromatic intermediates change into CO2 and H2O. The results indicate that benzoic acid and benzaldehyde are the main accumulation because of their high reaction energy. A possible reaction mechanism is proposed for toluene oxidation, deactivation, and regeneration of catalysts, which has a significant value for guiding the practical applications.
63 citations
TL;DR: In this article, a noble metal-free photocatalyst for the highly efficient and simultaneous generation of hydrogen and the selective oxidation of benzyl alcohol into benzaldehyde over CdS@MoS2 heterostructures under visible light was reported.
Abstract: Photocatalytic hydrogen production coupled with selective oxidation of organic substrates to produce high-value-added fine chemicals has drawn increasing attention. Herein, we report a noble metal-free photocatalyst for the highly efficient and simultaneous generation of hydrogen and the selective oxidation of benzyl alcohol into benzaldehyde over CdS@MoS2 heterostructures under visible light. Without the need for a sacrificial agent, CdS@MoS2 displayed an excellent hydrogen production rate of 4233 µmol g−1 h−1 with 0.3 mmol benzyl alcohol, which is approximately 53 times higher than that of bare CdS nanorods (80 µmol g−1 h−1). The reaction system was highly selective for the oxidation of benzyl alcohol into benzaldehyde. When the amount of benzyl alcohol increased to 1.0 mmol, the hydrogen production reached 9033 µmol g−1 h−1. Scanning electron microscopy and transmission electron microscopy images revealed that p-type MoS2 sheets with a flower-like structure closely adhered to n-type semiconductor CdS nanorods through the formation of a p-n heterojunction. As a potential Z-scheme photocatalyst, the CdS@MoS2 heterostructure effectively produces and separates electron-hole pairs under visible light. Thus, the electrons are used for reduction to generate hydrogen, and the holes oxidize benzyl alcohol into benzaldehyde. Moreover, a mechanism of photogenerated charge transfer and separation was proposed and verified by photoluminescence, electrochemical impedance spectroscopy, photocurrent and Mott-Schottky measurements. The results reveal that the CdS@MoS2 heterojunctions have rapid and efficient charge separation and transfer, thereby greatly improving benzyl alcohol dehydrogenation. This work provides insight into the rational design of high-performance Z-scheme photocatalysts and the use of holes and electrons to obtain two valuable chemicals simultaneously.
59 citations
TL;DR: The metal-organic frameworks (MOFs) are an emerging class of catalyst materials that present the opportunity to develop Lewis acid catalysts with uniform, well-defined, tunable, isolated active sites.
Abstract: Metal–organic frameworks (MOFs) are an emerging class of catalyst materials that present the opportunity to develop Lewis acid catalysts with uniform, well-defined, tunable, isolated active sites f...
59 citations
TL;DR: In this paper, it was shown that the rates, reaction orders and activation energies for TCH and ECH of phenol and benzaldehyde on Pd, Pt, and Rh can be explained with a simple kinetic model based on similar Langmuir-Hinshelwood mechanisms.
54 citations
TL;DR: In this paper, a graphene-based acid catalyst, GO-PrSO3H, was prepared through a simple two-step process, where surface modification with 3-mercaptopropyl trimethoxysilane followed by oxidation of sulfide groups led to the production of sulfonic acid sites on graphene oxide nanosheets.
45 citations
TL;DR: The 3D metal-organic frameworks (MOFs) [Co(1κN; 2κOO′-μ-L)2]n.4n(DMF) and [Zn2(1kN;2κO-μL) 2(κO4-μ4-BTC)n.5n(H2O) were synthesized from the pyridyl amide functionalized benzoic acid (HL).
43 citations
TL;DR: In this article, the magnetically reusable Fe3O4-cellulose-copper nanocomposite was synthesized through a green synthesis method using Ceratonia siliqua aqueous extract as a reducing and stabilizing agent.
TL;DR: The enhancement of electrocatalytic reduction is realized by the participation of support‐generated hydronium ions in the proximity of the metal particles, and the hydrogenation rate is not affected when H2 is used as a reduction equivalent.
Abstract: Acid functionalization of a carbon support allows to enhance the electrocatalytic activity of Pd to hydrogenate benzaldehyde to benzyl alcohol proportional to the concentration of Bronsted-acid sites. In contrast, the hydrogenation rate is not affected when H2 is used as a reduction equivalent. The different responses to the catalyst properties are shown to be caused by differences in the hydrogenation mechanism between the electrochemical and the H2 -induced hydrogenation pathways. The enhancement of electrocatalytic reduction is realized by the participation of support-generated hydronium ions in the proximity of the metal particles.
TL;DR: In this paper, an atomic-scale oxide decoration catalytic structure is designed and implemented by atomic layer deposition (ALD), which shows enhanced conversion and selectivity simultaneously, thus a high yield of benzaldehyde is obtained.
TL;DR: In this article, the performance of a series of CeO2 supports with different morphologies, e.g., rod, cube, and polyhedron, was investigated for benzyl alcohol oxidation in the absence of solvent.
TL;DR: A novel catalyst which carbon hybrid supported platinum nanoparticles were synthesized by this group for the oxidation of benzyl alcohol derivatives to benzaldehyde compounds in aqueous toluene at 80 °C, providing ≤95% conversion after its 3rd consecutive use in the oxidation reaction of various compounds.
Abstract: A novel catalyst which carbon hybrid supported platinum nanoparticles
were synthesized by our group for the oxidation of benzyl alcohol derivatives. In
this study, this catalyst was utilized for the oxidation of benzyl alcohol
derivatives to benzaldehyde compounds in aqueous toluene at 80 °C. The benzaldehyde
derivatives were synthesized in high yields and mild conditions in the presence of
the catalyst by the developed method. Additionally, the prepared nanoparticles have
been characterized by Transmission Electron Microscopy (TEM), the high-resolution
electron micrograph (HR-TEM), X-ray Photoelectron Spectroscopy (XPS), and X-ray
Diffraction (XRD). The mean particle size of the nanoparticles determined by the XRD
technique was found to be 2.83 nm in parallel with TEM analysis. TEM analysis also
indicated that the Pt nanoparticles were evenly dispersed on the support material.
Finally, the Pt@CHs catalyst was shown also stable and reusable for the oxidation
reaction, providing ≤95% conversion after its 3rd consecutive use in the oxidation
reaction of various compounds.
15 Dec 2020
TL;DR: In this paper, a milder approach for the fabrication of NiFe2O4 nanoparticles (NPs) for use as a catalyst in the selective oxidation of benzyl alcohol to benzaldehyde was explored.
Abstract: Benzaldehyde is one of the most important and versatile organic chemicals for industrial applications. This study explores a milder approach for the fabrication of NiFe2O4 nanoparticles (NPs) for use as a catalyst in the selective oxidation of benzyl alcohol to benzaldehyde. A co-precipitation method coupled with hydrothermal aging has been adopted to synthesize NiFe2O4 NPs in the absence of any additive. Different techniques such as electron microscopy, diffractometry, and photoelectron spectroscopy have been used to characterize the products. The results showed that the synthesized NiFe2O4 NPs are spherical, pure, and highly crystalline with sizes below 12 nm possessing superparamagnetic behaviour. The catalytic activity of the synthesized NiFe2O4 NPs has been assessed in the selective oxidation of benzyl alcohol under ambient reaction conditions. A conversion of 85% benzyl alcohol with 100% selectivity has been attained with t-butyl hydroperoxide at 60 °C in 3 h. With the optimized reaction conditions, the generality of the newly developed protocol has been expanded to a wide array of substituted benzyl alcohols with good performance. The NiFe2O4 nanocatalysts are magnetically separable and are reusable up to five cycles without loss of catalytic activity.
TL;DR: Selective photooxidation of toluene to benzaldehyde using O2 as an oxidant has the advantages of mild reaction conditions and excellent atomic economy, but it often suffers from low conversion effi ciency as discussed by the authors.
Abstract: Selective photooxidation of toluene to benzaldehyde using O2 as an oxidant has the advantages of mild reaction conditions and excellent atomic economy, but it often suffers from low conversion effi...
TL;DR: In this paper, a novel hybrid K6(H2O)8H24(C26H16N4O4)8[P6W48Fe6O180]·6H 2O (FeW-DPNDI) was firstly synthesized by incorporating a rare Fe-substituted trimeric Dawson derivative and photosensitizer N,N'-bis(4-pyridylmethyl)naphthalene diimide (DPND) via solvothermal method.
TL;DR: When benzaldehyde and furfural were present in the actual concentration ratio determined in Huangjiu, the enhancement of the Qu and sweet aromas became significant, which indirectly indicated synergy between them, and these compounds could increase or decrease the intensity of sensory descriptors even at subthreshold concentrations.
TL;DR: A newly Schiff base, 4amino-N-benzylidene-(4-BAB) protection ability was synthesised from a condensation reaction of 4-aminobenzamide (4-AB) and benzaldehyde (BA).
Abstract: A newly Schiff base, 4-amino-N-benzylidene-benzamide (4-BAB) protection ability was synthesised from a condensation reaction of 4-aminobenzamide (4-AB) and benzaldehyde (BA). Adsorption and...
TL;DR: The designed enzyme cascade could efficiently convert L-Phe into benzyl alcohol with molar conversion above 99% and has great potential to produce various high-valued fine chemicals.
Abstract: Benzyl alcohol is a naturally occurring aromatic alcohol and has been widely used in the cosmetics and flavor/fragrance industries. The whole-cell biotransformation for synthesis of benzyl alcohol directly from bio-based L-phenylalanine (L-Phe) was herein explored using an artificial enzyme cascade in Escherichia coli. Benzaldehyde was first produced from L-Phe via four heterologous enzymatic steps that comprises L-amino acid deaminase (LAAD), hydroxymandelate synthase (HmaS), (S)-mandelate dehydrogenase (SMDH) and benzoylformate decarboxylase (BFD). The subsequent reduction of benzaldehyde to benzyl alcohol was achieved by a broad substrate specificity phenylacetaldehyde reductase (PAR) from Solanum lycopersicum. We found the designed enzyme cascade could efficiently convert L-Phe into benzyl alcohol with conversion above 99%. In addition, we also examined L-tyrosine (L-Tyr) and m-fluoro-phenylalanine (m-f-Phe) as substrates, the cascade biotransformation could also efficiently produce p-hydroxybenzyl alcohol and m-fluoro-benzyl alcohol. In summary, the developed biocatalytic pathway has great potential to produce various high-valued fine chemicals.
TL;DR: In this article, a series of hexadecylphosphate acid (HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of oil and water with the catalysts as stabilizers.
TL;DR: In this article, the effect of catalyst preparation method and metal precursors on the catalyst basicity was studied in Pd catalysts supported on magnetic SBA-15 for benzyl alcohol oxidation (BzOH) to benzaldehyde (bzH).
TL;DR: In this article, a modified solgel process from their precursor salts was used to obtain a mixture of Bi-and Ce-based mixed oxides for the Koevenagel condensation of benzaldehyde and diethyl malonate and the toluene oxidation to benzaldehyde reactions.
TL;DR: In this paper, the impact of four metals (Au, Cu, Pd and Pt) on the two carbonyl reduction pathways, i.e., direct electrochemical reduction to benzyl alcohol and reductive C-C coupling to a diol product, was investigated.
TL;DR: The MCMSalenNi was used in the rapid oxidation of benzyl alcohol and it afforded a high conversion (~98%) with benzaldehyde as the major product within 90min this paper.
TL;DR: In this paper, a blue-to-green light-responsive semiconductor photocatalyst was used for the selective oxidation of toluene to benzaldehyde under visible light irradiation.
TL;DR: In this paper, a spray-dried g-C3N4/TiO2 granules (TCNg) was developed for the photocatalytic oxidation of benzyl alcohol to benzaldehyde.
TL;DR: In this article, the authors showed that the 10Fe−15Mn/γ-Al2O3 catalysts that prepared by the wet-impregnation method were used to degrade toluene, a VOCs model compound.
Abstract: Fe–Mn/γ-Al2O3 catalysts that prepared by the wet-impregnation method were used to degrade toluene, a VOCs model compound. The results indicated that the 10Fe–15Mn/γ-Al2O3 exhibited 95% of toluene conversion as well as 95% of CO2 yield at 300 °C. The Fe–Mn/γ-Al2O3 showed a better toluene oxidation activity with respect to the Fe/γ-Al2O3 and Mn/γ-Al2O3. The introduction of Fe into the Mn/γ-Al2O3 resulted in higher surface area, higher Mn3+/(Mn3+ + Mn4+) ratio, lower reduction temperature, and homogenous distribution of Mn. Meanwhile, the co-exist of the Fe3+ and Mn3+ over the 10Fe–15Mn/γ-Al2O3 also favored for the oxygen transfer, which may enhance the catalytic oxidation performance. The initial toluene was adsorbed on surface of the catalysts and formed benzoyl oxide (C6H5–CH2–O), and then the benzoyl oxide (C6H5–CH2–O) was oxidized to benzaldehyde. Furthermore, the benzaldehyde was further oxidized to form benzoic acid that could be converted to CO2 and H2O.
TL;DR: In this paper, the gas-phase oxidation of benzaldehyde was investigated in a jet-stirred reactor, and 48 species were detected using gas chromatography, mainly CO, CO2 and phenol.