Benzyl Phenyl Ether Research Articles

Pd Nanoparticles Decorated CeZrOx for Enhanced Photocatalytic Hydrogenation of Biomass‐Derived Compounds

The photocatalytic conversion of biomass‐derived compounds into value‐added chemicals presents a promising protocol for the sustainable production of renewable chemicals. Our study explores the hydrogenation of biomass model compounds under visible light illumination. Zr was incorporated into the CeO2 framework, forming a CeZrOx(1:0.5) solid solution, confirmed by powder X‐ray diffraction (PXRD) and X‐ray photoelectron spectroscopy (XPS) analyses. The light uptake capacity of the CeZrOx solid solution was characterized using UV‐visible spectroscopy. Additionally, the band structure of the CeZrOx solid solution was assessed using valance band X‐ray photoelectron spectroscopy (VB‐XPS) and Ultraviolet photoelectron spectroscopy (UPS) analysis, revealing a Z‐Scheme, which was further confirmed by various control experiments. Upon decorating the CeZrOx(1:0.5) solid solution with 1 wt% palladium (Pd), the resulting 1Pd/CeZrOx(1:0.5) composite exhibited improved charge separation and enhanced visible light absorption capacity. This composite achieved ~99% conversion of furfural to tetrahydrofurfuryl alcohol under a 15 W blue LED illumination and 0.2 MPa hydrogen. Similarly, it demonstrated ~99% conversion of benzyl phenyl ether (BPE) to toluene and phenol under a 10 W blue LED illumination. Our findings elucidate the active sites and demonstrate the recyclability of mixed metal oxides for selective furfural hydrogenation and BPE hydrogenolysis under visible light.

Study on the efficient electrocatalytic depolymerization of α-O-4 bond in lignin assisted by simple electrolyte

Lignin is anticipated to serve as a replacement for dwindling fossil fuel resources owing to its abundant sources and renewable nature. The electrochemical oxidation technique for depolymerizing lignin has garnered significant interest for its environmentally friendly and mild operating conditions. Nevertheless, the current utilization of auxiliary electrolytes, predominantly organic bases, ionic liquids, and other specialized substances, poses a constraint on the widespread adoption of this approach. Furthermore, there is a scarcity of instances where electrochemical technology has been employed to depolymerize the α-O-4 bond in lignin for the production of highly selective acetals. In this study, a sodium chloride/methanol (NaCl/MeOH) system was utilized for the direct depolymerization of the α-O-4 bond in a lignin model molecule, specifically benzyl phenyl ether (BPE). The optimal conditions resulted in a 95.2 % conversion rate of the BPE substrate and a high yield of 94.5 % for the main product, benzaldehyde dimethyl acetal(Bda). This research offers a promising approach for the electrocatalytic depolymerization of α-O-4 bonds in lignin, leading to the selective production of acetal chemicals using a common auxiliary electrolyte at room temperature in just 2 h.

Rhombohedral ZnIn2S4-Catalysed Anodic Direct Electrochemical Oxidative Cleavage of C-O Bond in α-O-4 Linkages in Ambient Conditions

The electrochemical selective oxidative transformation of biomass feedstocks into valuable oxygenated fine chemicals that are essential to the bio-commodity chemical markets. In this study, we used a rhombohedral ZnIn2S4 (R-ZIS) electrocatalyst to realise the efficient anodic cleavage of C-O bonds in benzyl phenyl ether (BPE), an α-O-4 lignin model compound, to a series of industrially relevant oxygenated mono-aromatics (benzyl alcohol, benzaldehyde, benzoic acid, etc.). In optimised conditions, the reaction achieved over 99% conversion rate with a Faraday efficiency of 51.6% that greater than most known electrocatalytic oxidative cleavage examples. The ZnIn2S4 electrocatalyst was deposited on a carbon support, and its structural properties and surface morphology were extensively investigated. Systematic chronoamperometric electrolysis coupled with18O isotopic labelling confirmed that C-O scission occurred exclusively between the benzylic carbon and phenolic oxygen. The experimental results were supported by density functional theory calculations. The substrate scoping study revealed the suitability of the R-ZIS induced electrocatalytic system for a variety of substituted lignin α-O-4 and β-O-4 model dimers. Overall, this work demonstrates an efficient anodic process that can enable the atom-efficient valorisation of lignin to produce oxygenated fine chemicals. Figure 1

ZnIn2S4-Catalyzed Anodic Direct Electrochemical Oxidative Cleavage of C-O Bonds in Alpha-O-4 Linkage in an Aqueous Environment

Electrochemical selective oxidative cleavage of biomass-derived lignin feedstocks, such as C-O bond, into high-value oxygenated fine chemicals and pharmaceutical products offers an emerging route for biomass valorization. Here, we developed an efficient anodic valorization of α-O-4 lignin model compound benzyl phenyl ether (BPE) to the desirable monoaromatics products via the C-O bond direct cleavage at ZnIn2S4 anode under +1.6-2VAg/AgCl supply. A series of carbon-supported ZnIn2S4 electrodes with different hexagonal and rhombohedral phase distributions were carefully controlled and exhibited over 99% BPE conversion with specific C-O bond selectivity. We then studied substrate competition to compare the electrocatalytic performance of different ZnIn2S4 crystal phases. The experimental results were supported by density functional theory calculations. The substrate scope study revealed the suitability of the R-ZIS induced electrocatalytic system for a variety of substituted lignin α-O-4/β-O-4 model dimers. Overall, this work provides an efficient electrode and approach for enabling atom-efficient electro-refinery of diverse lignin-derived oxygenated chemicals.

Mechanocatalytic Hydrogenolysis of the Lignin Model Dimer Benzyl Phenyl Ether over Supported Palladium Catalysts.

This work demonstrates the mechanocatalytic hydrogenolysis of the ether bond in the lignin model compound benzyl phenyl ether (BPE) and hardwood lignin isolated by hydrolysis with supercritical water. Pd catalysts with 4 wt % loading on Al2O3 and SiO2 supports achieve 100% conversion of BPE with a toluene production rate of (2.6-2.9) × 10-5 mol·min-1. The formation of palladium hydrides under H2 gas flow contributes to an increase in the turnover frequency by a factor of up to 300 compared to Ni on silica-alumina. While a near-quantitative toluene yield is obtained, some of the phenolic products remain adsorbed on the catalyst.

The efficient and directional electrocatalytic depolymerization of α-O-4 bond in lignin by auxiliary electrolyte

This study examines the use of tetrabutylammonium tetrafluoroborate (TBABF4) as a catalyst for the depolymerization of lignin and its model compound without the addition of oxidants. The impact of electrolytes, reaction times, and solvents on the cleavage of the α-O-4 bond in lignin is investigated. The experimental setup includes specific conditions such as the use of carbon cloth (CC) as the counter electrode and a platinum plate as the working electrode. The TBABF4 catalyst effectively cleaved the α-O-4 bond in the lignin model molecule with notable selectivity and minimal formation of by-products, resulting in a substantial conversion rate of benzyl phenyl ether (95.7 %) and a high yield of benzaldehyde dimethyl aceta (92.4 %) under specific conditions. This investigation showcases a mild electrochemical catalytic depolymerization approach for lignin model molecules at ambient temperature, thereby presenting novel avenues for further exploration in the field.

Does the Oxygen Functionality Really Improve the Thermodynamics of Reversible Hydrogen Storage with Liquid Organic Hydrogen Carriers?

Liquid organic hydrogen carriers (LOHCs) are aromatic molecules that are being considered for the safe storage and release of hydrogen. The thermodynamic properties of a range of aromatic ethers were investigated using various experimental and theoretical methods to assess their suitability as LOHC materials. The absolute vapour pressures were measured for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene using the transpiration method. The standard molar enthalpies and entropies of vaporisation/sublimation were derived from the temperature dependence of the vapour pressures. The combustion energies of benzyl phenyl ether and dibenzyl ether were measured using high-precision combustion calorimetry, and their standard molar enthalpies of formation were derived from these data. High-level quantum chemical calculations were used to calculate the standard molar enthalpies of formation in the gas phase for benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene. The latter values agreed very well with the experimental results obtained in this work. The thermodynamic properties of the hydrogenation/dehydrogenation reactions in liquid phase in LOHC systems based on methoxy–benzene, diphenyl ether, benzyl phenyl ether, dibenzyl ether and 2-methoxynaphthalene were derived and compared with the data for similarly structured hydrogen carriers based on benzene, diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane and naphthalene. The influence of the oxygen functionality on the thermodynamic properties of the hydrogenation/dehydrogenation reactions was evaluated.

Regulation of co-pyrolysis behavior of Naomaohu coal and polypropylene by controlling the cracking of polypropylene pyrolysis volatiles

Pyrolysis is one of the technologies for clean and efficient conversion and utilization of coal, however, low yield and poor quality of tar restrict its utilization. Waste polypropylene (PP) could be efficiently used to improve tar yield of low-rank coal via co-pyrolysis. To strengthen the generation and transfer of hydrogen-rich radicals, modified HZMS-5 (HZ5) catalyst was used to regulate the composition of PP pyrolysis volatiles. Results show that close contact between HZ5 catalyst and coal favors the formation of light components, which reaches the maximum value of 72.45 wt%. In the presence of zeolite catalysts modified with 0.2 mol/L NaOH (0.2Na-HZ5), light oil in tar exhibits an obvious increase of 12.78 % compared with HZ5. A synergetic effect analysis clarifies that C2-C3 produced from PP pyrolysis under the action of the catalyst participate in the formation of tar. And the reactive intermediates from secondary cracking of PP volatiles over 0.2Na-HZ5 promote the cleavage of O-containing groups in coal, leading to the increase of phenols and alcohols in tar. The co-pyrolysis behavior of benzyl phenyl ether /bibenzyl and PP is shown that the transfer of oxygenated compounds into liquid is enhanced, confirming a positive synergetic effect. Meanwhile, the clear inhibition of C2-C3 components further indicates their contribution to tar formation.

Mesoporous SBA‐15 Supported CdS through Organosilane Ligand for Photo Driven Cleavage of Aryl Ether in Lignin and its Model Compound

AbstractMesoporous silica (SBA‐15) was synthesized hydrothermally followed by calcination and then functionalization with 3‐(triethoxysilyl)‐1‐propanethiol through surface grafting. The thiol moiety of the grafted ligand was utilized for the uniform anchoring of cadmium into the channels of the material. The synthesised material was subjected for its photo catalytic applications after characterization through standard characterization protocol. The synthesised mesoporous silica (i.e. SAB‐15), ligand modified material (i.e.SBA‐15‐S and Cd loaded ( i.e. SAB‐15‐CdS) materials were characterized through standard characterization protocol like powder XRD, FT‐IR, UV‐DRS, MAS NMR, N2 sorption, FE‐SEM, HR‐TEM and TG‐DTA studies. After successful characterization, the screening of the catalyst was carried out on a model reaction involving photo catalytic cleavage of α‐O‐4 aryl ether linkage present in benzyl phenyl ether, which is an important lignin model compound. The catalyst exhibited good efficiency along with the selectivity for desired monoaromatic platform chemicals. The synthesized catalyst was also carried out for the photo catalytic depolymerization of alkali lignin at the optimized reaction conditions which further showed the promising results for getting value added chemicals from lignin. The reaction products were characterized by using Gas chromatography‐mass spectrometry (GC‐MS) techniques.

Porous hollow nanospheres nickel phosphide and its high catalytic hydrogenation performance on naomaohu coal soluble portion and model compounds

The catalytic conversion of oxygen-containing aromatic ring in lignite under mild conditions is crucial to obtain clean liquid fuel. Here, hollow nanosphere Ni3P-500–24 catalysts were prepared at a calcination temperature of 500 °C and acid-etching time of 24 h. The porous hollow nanospheres structure could expose more catalytic sites, and the electron-rich nickel exhibited a good catalytic activity. The conversion rate of benzyl phenyl ether (BPE) was 100 % (140 ℃, 1 MPa H2, 2 h), and the main products were methylcyclohexane and cyclohexanol, indicating that the catalyst had good catalytic hydrocracking performance. In addition, the catalyst exhibited certain deoxygenation activity and high product selectivity for other oxygen-containing model compounds. For the catalytic hydrogenation of Naomaohu coal (NMHC) soluble portion, the content of alkanes increased from 19 % to 47 %, while the content of oxygen-containing compounds decreased from 56 % to 21 %, which further demonstrate that the catalyst have good catalytic hydrogenation and deoxygenation performance. Density Functional Theory (DFT) calculations showed that the properties of the Ni3P-500–24 catalyst was similar to noble metal, which could activate H2 to produce two kind of active hydrogen: H radical and diatomic hydrogen. The synergistic pathways for the transfer of active hydrogen during the catalytic hydroconversion (CHC) process were analyzed. Above results could provide theoretical guidance for the conversion of lignite into high-quality clean liquid fuels.

Nitrogen-doped carbon supported iron nanoparticles for mild catalytic hydrocracking of Xilinguole lignite

Cleaving C-O bridged bonds of lignite via catalytic hydrocracking (CHC) is an effective method to produce chemicals and clean fuels. Herein, a nitrogen-doped carbon supported Fe catalyst was developed by using a one-pot method for CHC of Xilinguole lignite (XL) and its related model compounds. The doped nitrogen enhanced the interaction between Fe and N species to form Fe-N sites and favored forming smaller Fe/Fe3C nanocrystals, which played a crucial role in CHC performance. Toluene and phenol were produced from CHC of benzyl phenyl ether (BPE) with high yield and selectivity at 250 °C over the optimal catalyst with 4% Fe, without hydrogenation products. The Fe-based catalyst activated both H2 and isopropanol to generate hydrogen radicals for cleaving C-O bridged bonds. The CHC of XL under different temperature and time showed that the yields of oil, asphaltene and preasphaltene were obviously promoted under 325 °C, 1 MPa, and 6 h, and they had much higher H/C ratio but remarkably lower O/C ratio, resulting in much higher heating values (28.19–36.90 MJ/kg) than XL. Phenols were the major group component with relative content of 53.6 wt% in oil from CHC, and the asphaltene and preasphaltene from CHC had obviously lower molecular weights, which could attributed to depolymerization of C-O bridged bonds in the XL macromolecular structures over the catalyst.

Polydopamine-Modified Magnetic Nanoparticles (Fe3O4@PDA) for the Copper-Catalyzed Ipso-Hydroxylation of Arylboronic Acids and Subsequent O-Benzylation in Aqueous Media

Abstract: A novel advancement has emerged in the realm of catalysis with the development of an innovative method for the ipso-hydroxylation of arylboronic acids. This approach harnessed the power of bio-compatible polydopamine-coated magnetite support (Fe3O4@PDA) in conjunction with a copper salt, forming a heterogeneous catalytic environment. The resulting catalytic system facilitated oxidative hydroxylation under mild aerobic conditions at room temperature in aqueous conditions. This environmentally friendly process allowed for the seamless conversion of diverse arylboronic acids featuring varying electron-withdrawing or electron-donating groups into the corresponding phenols, achieving remarkably high yields. Notably, the versatility of the catalytic system extended to a one-pot tandem O-benzylation of the resultant phenolic intermediates. The additional dimension of the process underscores its efficiency, offering a streamlined route to synthesizing benzyl phenyl ethers with a commendable level of success. The significance of the present catalytic methodology lies not only in its efficacy but also in its eco-friendly attributes, showcasing the potential for sustainable and efficient transformations in organic synthesis.

Degradation of the strobilurin fungicide mandestrobin in illuminated water-sediment systems.

The degradation behavior of mandestrobin (1) was investigated in aerobic aquatic water-sediment systems exposed to continuous artificial sunlight (λ>290 nm). [14C]mandestrobin uniformly labeled at the phenoxy or benzyl ring was individually applied to the overlying water of the system at a rate equivalent to 262.5 g a.i./ha. The transformation of 1 was mainly proceeded via photoinduced bond cleavage at the benzyl phenyl ether and the subsequent rearrangement reaction. Interestingly, some of the photodegradates and microbial metabolites of 1 observed in the aquatic photodegradation and water-sediment (dark) studies, respectively, were never detected. Furthermore, the observed photoproducts were less formed and were steadily degraded or metabolized to carbon dioxide or strongly adsorbed to bottom sediment. The fate of 1 and its degradates in illuminated water-sediment systems was considered to reflect realistic conditions more precisely, as it accounts for various effects attributed to sunlight.

Insight into the pyrolysis mechanism of α-O-4 linked lignin: The role of bimolecular interactions and substituents

Pyrolysis can convert lignin into various high-value phenolic derivatives, whereas the pyrolysis mechanism of lignin, particularly the α-O-4 linked lignin, has not been clearly revealed. Herein, unsubstituted α-O-4 lignin dimer benzyl phenyl ether (BPE) and Cα-substituted α-CH2OH-BPE, α-(CH2)2OH-BPE and α-CHOHCH2OH-BPE were employed to study the radical and concerted mechanisms of α-O-4 type lignin pyrolysis by density functional theory (DFT) calculation and electronic structure analysis. A pyrolysis system was constructed to carefully consider unimolecular and bimolecular reactions, and the influence of substituent groups was investigated. The results indicate that unsubstituted α-O-4 structure can only undergo unimolecular Cα–O homolysis without hydrogen transfer, while various substituents provide more hydrogen sites, leading to the occurrence of radical chain reactions and concerted reactions. Cβ–dehydrogenated radicals derived from substituted α-O-4 dimers can be easily generated by intermolecular Cβ–hydrogen abstraction, which tends to break the Cα–O bond. Similarly, hydroxyl-assisted hydrogen transfer (AHT) can promote Cα–O cleavage by inducing Cβ/Cγ–hydrogen exchange of substituted hydroxy groups. Comprehensively, both radical hydrogen abstraction and concerted hydroxyl-AHT interactions have positive effects on the Cα–O decomposition of α-O-4 linkage. This study provides a more reasonable explanation for the initial decomposition of α-O-4 linked lignin and the preliminary generation of phenolic hydroxy and phenoxy radical derivatives.

Impact of Acidity and Metal Particle Size on the Competitive Pathways of Benzyl Phenyl Ether Conversion to Aromatics and Cycloalkanes in a Nonpolar Solvent

Impact of Acidity and Metal Particle Size on the Competitive Pathways of Benzyl Phenyl Ether Conversion to Aromatics and Cycloalkanes in a Nonpolar Solvent

Insights into the Relationship between the Microstructure and the Catalytic Behavior of Fe2(MoO4)3 during the Ethanolysis of Naomaohu Coal.

Ethanolysis is an effective method to depolymerize weak bonds in lignite under mild conditions, which can result in the production of high-value-added chemicals. However, improving ethanolysis yield and regulating its resulting product distribution is a big challenge. Hence, exploiting highly active catalysts is vital. In this work, Fe2(MoO4)3 catalysts with zero-dimensional nanoparticles, one-dimensional (1D) nanorods, two-dimensional (2D) nanosheets, and three-dimensional (3D) nanoflower structures were successfully prepared and applied in the ethanolysis of Naomaohu coal. The results showed that for all samples, the yield of ethanol-soluble portions (ESP) was significantly improved. The highest yield was obtained for the Fe2(MoO4)3 nanorods, with an increase from 28.84% to 47.68%, and could be attributed to the fact that the Fe2(MoO4)3 nanorods had a higher number of exposed active (100) facets. In addition, the amounts of oxygen-containing compounds, such as ethers, esters, and phenols, increased significantly. The mechanism of ethanolysis catalyzed by the Fe2(MoO4)3 nanorods was also studied using phenylbenzyl ether (BOB) as a model compound. BOB was completely converted at 260 °C after 2 h. It is suggested that Fe2(MoO4)3 nanorods can effectively break the C-O bonds of coal macromolecules, thus promoting the conversion of coal.

Pd Nanoparticle-Decorated Bi2MoO6 Nanoflakes with Surface Oxygen Vacancies for Selective Room-Temperature Furfural Hydrogenation and Benzyl Phenyl Ether Hydrogenolysis

Pd Nanoparticle-Decorated Bi₂MoO₆ Nanoflakes with Surface Oxygen Vacancies for Selective Room-Temperature Furfural Hydrogenation and Benzyl Phenyl Ether Hydrogenolysis

Ruthenium catalysts supported on activated carbon from corncob waste for selective hydrogenolysis of C–O bonds in lignin-derived aromatic compounds

Selective hydrogenolysis of C–O bonds in lignin is regarded as an important process to produce high value-added chemicals and biofuels. Herein, high-performance Ru-based catalysts (Ru/AC) supported on activated carbon (AC) derived from corncob waste were prepared by a simple impregnation method. The optimal 5%Ru/AC possessed enormous specific surface area, well-developed porosity, high metal dispersion, small Ru particle size and strong metal-support interaction, showing a marvelous catalytic performance in the hydrogenolysis of diphenyl ether, benzyl phenyl ether and phenylethyl phenyl ether with different kinds of C–O bonds under mild conditions. Besides, various phenolic compounds were selectively hydrogenated into cycloalkanols and cycloalkanes over 5%Ru/AC, indicating the excellent catalytic activity in aromatic ring hydrogenation of this catalyst. In addition, high conversion of diphenyl ether and high selectivity of monomeric products were well maintained after employing this catalyst at least three times. The construction and application of the ingenious 5%Ru/AC catalyst highlighted a promising approach to the value-added utilization of lignin-derived aromatic compounds.

Novel Series of Peripherally Phthalocyanines (Zn, Pd and Cu): Spectroscopic Studies

Abstract:A new series of metallophthalocyanines (MPc) containing metals such as : Zn (II), Cu (II) and, Pd (II) were designed, synthesized, and characterized, using MS, IR and UV-Vis spectroscopy. A Suzuki cross-coupling reaction was investigated by using the Pd(dppf)Cl2 as a catalyst and cesium carbonate as a base to improve the yield of the precursor 2.6-di(pyridin-3-yl)- phenyl benzyl ether. The changes of metals, substituents, and positions increases the Q-band value from the monosubstituted to the octa-substituted macrocycles, and from Pd, to Cu to Zn complexes. All MPc showed quite similar IR spectra.

Catalytic transfer hydrogenolysis mechanism of benzyl phenyl ether over NiCu/Al2O3 using isopropanol as hydrogen source

Efficient transfer hydrogenolysis of benzyl phenyl ether (BPE) was accomplished over Ni1.5Cu1.5/Al2O3 using isopropanol as hydrogen source. The characterization results demonstrated that the formation of NiCu alloy and electron transfer between Ni and Cu were responsible for the excellent catalytic performance. Isopropanol displayed better hydrogen-donating ability than other low-carbon alcohols because of its unique dehydrogenation pathway and small steric hindrance. The results of isotopic experiments elucidated that active hydrogen species for the CO bond cleavage originated from isopropanol rather than H2, while both isopropanol and H2 were responsible for hydrogenation of phenol to cyclohexanol when reaction was conducted with mixed hydrogen sources. A mechanism study illustrated that transfer hydrogenolysis of BPE proceeded through direct cleavage of CO bond followed by phenol hydrogenation, in which the active hydrogen species were in the form of H+ and H−.