Catalyst For Oxidation Of Benzyl Alcohol Research Articles

Synthesis of a Novel Spherical-Shell-Structure Polymerized Ionic Liquid Microsphere PILM/Au/Al(OH)3 Catalyst for Benzyl Alcohol Oxidation

In order to selectively oxidize benzyl alcohol, a novel noble metal catalyst based on polymer ionic liquids with a core-shell structure was created. First, polymer ionic liquid microspheres (PILMs) were prepared by free radical polymerization. Second, the in situ adsorption of Au nanoparticles on the surface of PILMs was accomplished, thanks to the strong electrostatic interaction between N atoms and metal ions on the diazole ring of PILMs. Additionally, the introduction of Al(OH)3 prevented the aggregation of Au nanoparticles and promoted the catalytic reaction. Finally, the PILM/Au/Al(OH)3 catalyst with a core-shell structure was formed. The effectiveness of the PILM/Au/Al(OH)3 catalyst was assessed by varying the catalyst's type, quantity, amount of Au, amount of H2O2, temperature, and reaction time. After five cycles of experiments, the catalyst was effective and reusable. In addition, the potential catalytic mechanism of the catalyst in the oxidation of benzyl alcohol was proposed.

Ultrathin two-dimensional Ni–MOF with high-valence oxidation states as high-performance electrocatalytic catalysts for benzyl-alcohol oxidation

<p indent="0mm">Ultrathin two-dimensional metal-organic frameworks (2D MOFs) have large specific surface area and open catalytically-active centers, which have potential applications in electrocatalytic reactions. This work reports the ultrathin 2D Ni–MOF nanosheet arrays with open sites prepared by a mild solvothermal method and their applications in electrocatalytic benzyl-alcohol oxidation (EBO). As a high-performance EBO electrocatalyst, the 2D Ni–MOF shows low overpotential and superior durability. It only needs a potential of about <sc>1.50 V</sc> (<italic>vs</italic>. reversible hydrogen electrode (RHE)) to reach <sc>250 mA cm⁻²,</sc> and the oxidation efficiency is more than 85%. Compared with the 2D Ni(OH)₂ nanosheet arrays with the same ultrathin structure, the Ni–MOF exhibits good activity; its reaction overpotential is reduced by nearly 35 mV <sc>(@50 mA cm⁻²)</sc> and it has faster reaction kinetics. When benzyl alcohol oxidation is carried out at the same constant potential, the Ni–MOF has a higher response current. After continuous electrolysis for 20,000 s, the current density of <sc>25 mA cm⁻²</sc> can be retained, which is nearly twice as much as that of the Ni(OH)₂ nanosheets. It is shown that Ni in the Ni–MOF nanosheets has a higher oxidation state and is easier to be converted to NiOOH in EBO reactions, so that it can effectively catalyze the electrooxidation reaction of benzyl alcohol at a lower potential. This result will provide a new perspective for the further design of electrocatalysts with high performances for EBO reactions.

DFT assisted study on activation of surface acidic –COOH debris in graphene oxide supported catalyst for benzyl alcohol oxidation

This study is aimed to elucidate the deep intuitive understanding of whether carboxyl groups of graphene oxide (GO) are worth modifying for the selective oxidation of benzyl alcohol (BzA) to benzaldehyde (BzH). In this work, for the first time, Cu-salen complex (Where Salen = N,N’-bis(4-hydroxysalicylaldehyde)ethylenediamine) was grafted on chloro- modified GO nanosheets forming a heterogeneous catalyst (Cu-f-GO). First principles-based density functional theory (DFT) has been performed to inspect structural and electronic properties, binding mechanism of SOCl2 with each available functional group of GO. Besides, other parameters like HOMO, LUMO, energy bandgap (Eg), adsorption energy (Ead), electronegativity (χ), chemical potential (μ), and global electrophilicity were also calculated. The catalytic results show that the as-prepared catalyst demonstrated petite performance. This poor performance might be due to lesser acidic sites available on the surface of the catalyst. Hence, it was decided to substantiate the hypothesis, we have conducted the catalytic reaction using a few drops of concentrated H2SO4 as a precursor. The use of precursor had resulted in optimal activity with 100% conversion and 98.64% selectivity to BzH within 1 h.

Synthesis and Characterization of 3‐(Aryl azo)‐4‐hydroxy‐1,2‐naphthoquinone Ruthenium(III) Complexes as Catalysts for Benzyl Alcohol Oxidation

AbstractThe syntheses and characterization of 3‐(p‐substituted phenyl azo)‐4‐hydroxy‐l,2‐naphthoquinones ligands (L1‐3) and their Ru(III) complexes (Ru1‐3) are carried out. The characterization was ascertained by elemental analysis, thermal analysis, spectroscopic analyses (FT‐IR, 1H NMR, UV‐vis and Mass), magnetic, molar conductance, molecular calculations and electrochemical techniques. The green catalytic conversion of some benzyl alcohols to benzoic acid derivatives was successfully achieved by using these complexes in an aqueous KOH with K2S2O8 as co‐oxidant; with high yields by using Ru3 complex. Computational modeling was carried out to predict the structural geometry, magnetic characters and the electron donor/acceptor functions of the prepared complexes along with experimental results. The mechanism of benzyl alcohol oxidation was developed through an orange ruthenate‐persulfate reagent. The oxidation capacities of the ruthenium complexes were better than the other catalysts reported. The present results are useful to oxidize benzyl alcohols at an industrial scale with a good economy.

Mesostructured cellular foam silica supported Au–Pt nanoalloy: Enrichment of d-state electrons for promoting the catalytic synergy

A mesostructured cellular foam (MCF) silica was applied to support gold (Au) – platinum (Pt) alloy nanoparticles (NPs) for benzyl alcohol partial oxidation. A catalytic synergy on bimetallic gold (Au)-platinum (Pt) nanoparticle (NP) catalyst, referring to that introducing Au to Pt leading to a higher catalytic performance has been observed. However, the essence of this synergistic effect is still under debate. In this work, a series of MCF supported Au–Pt NP catalysts are designed to reveal the essence . Well-developed porous structure of MCF support eliminated the mass transfer limitation and intrinsic catalytic activity was obtained. The improved catalytic performance on bimetallic catalyst is attributed to the geometric and electronic changes of active sites after formation of Au–Pt alloy NPs. Compared with monometallic catalyst, the formation of Au–Pt alloy results in the changes of particle size and lattice structure. Electronic property analyses confirmed the increase of d state electrons on Au–Pt alloy NPs, which are calculated from s-p-d hybridization and intra-atomic charge redistribution, leading to the increased abundance of transferable d electrons near Fermi level and further enhancing the catalytic activity. These findings gain new insights into the catalytic synergy of bimetallic nanoparticles and shed light on the optimization of these catalysts. The catalytic synergy of mesostructured cellular foam silica supported bimetallic Au–Pt catalysts for benzyl alcohol oxidation is attributed to the increased abundance of transferable d electrons near Fermi level which are calculated from s-p-d hybridization and intra-atomic charge redistribution. • Mesostructured cellular foam silica support Au–Pt alloy nanoparticles were prepared by a facile one-pot method. • The formation of Au–Pt alloy nanoparticles results in particle size variation and lattice distortions. • Electron polarization leads to the increase of transferable d-orbital electrons on Au and Pt atoms. • The catalytic activity on Au–Pt alloy catalyst was enhanced through accelerating the O 2 activation.

Engineering ultrafine Pd clusters on laminar polyamide: A promising catalyst for benzyl alcohol oxidation under air in water

Polymer supports play an important role in noble metal loaded catalysts. In this study, palladium clusters stabilized by several polyamides have been widely studied in the oxidation of benzyl alcohol under airflow. The different kinds of polyamides (PADs) were synthesized with aromatic diamines and trimesoyl chloride by mechanical grinding method and solvent-heat method. Polyamide support was synthesized through mechanical grinding method. And the laminar structure and abundant amide bonds of polyamide can help obtain ultrafine Pd clusters with a mean particle size of 1.76 nm. The Pd0.5@PAD-2-M effectively catalyzed benzyl alcohol into benzaldehyde with a conversion of 96.1 % and turnover number (TON) of 1441 under 90 °C in water which was 2.5 times higher than the commercial Pd/C catalyst. High TON value of 6505 was also achieved in solvent-free system. This work reveals the advantages of laminar structure of polyamide in dispersing Pd clusters and promoting benzyl alcohol conversion. Besides, the carrier properties of amphipathy and substrate adsorption were also investigated to illustrate the significance of interfacial effect for laminar catalyst in heterogeneous catalysis.

Peroxotungstate-Based Ionic Hybrid as a Triphase Heterogeneous Catalyst for Efficient Benzyl Alcohol Oxidation Under Mild Conditions

Supported ionic-liquid-phases (SILPs) were synthesized via reaction of 1-methyl-3-(3-triethoxysilylpropyl)imidazolium hexafluorophosphate (ImCl-PF6) with SBA-15 and then peroxotungstate molecules were immobilized on SILPs. The resulting material (W-ImCl-PF6-SBA-15) was characterized via 29Si MAS NMR to detect the chemical environment around Si and its textural and thermogravimetric behavior were determined. To obtain insight into the role of ImCl-PF6 during catalysis, an ImCl-PF6-free catalyst (W/SBA-15) was also synthesized. W-ImCl-PF6-SBA-15 and W/SBA-15 were investigated as catalysts for benzyl alcohol oxidation, as a model reaction, under solvent-free conditions with H2O2.The presence of ImCl-PF6 was crucial for obtaining excellent catalytic activity, and W-ImCl-PF6-SBA-15 showed higher activity and stability than these of W/SBA-15. Optimized reaction conditions were employed to several selected alcohols oxidation and, remarkably, excellent aldehydes selectivity was achieved. The importance of ImCl-PF6-functionalized SBA-15 was evidenced via recycling experiments of benzyl alcohol oxidation, and W-ImCl-PF6-SBA-15 was recycled for ten reaction runs without significant change in benzyl alcohol conversion, benzaldehyde selectivity, and tungsten content.

One-, two- and three-dimensional coordination polymers based on copper paddle-wheel SBUs as selective catalysts for benzyl alcohol oxidation

Copper-based coordination polymers, Cu2(μ2-MeCO2)4(DABCO) (1), [Cu(1,4-BDC-Br)(DABCO)0.5]. xDMF.yH2O (2) and Cu(1,4-BDC-OH)(DMF) (3) (1,4-BDC-Br = 2-bromoterephthalate, DABCO = triethylenediamine, 1,4-BDC-OH = 2-hydroxyterephthalate) were solvothermally synthesized. Two polymorphs of 1 (1a and 1b) were obtained which both contain 1-D chains with similar connectivity and different packing. Compound 2 is a 3-D metal-organic framework (MOF) and 3 exhibits a 2-D structure. Structural analyses of the coordination polymers showed that they all have similar paddle-wheel secondary building units (SBUs). The coordination polymers 1–3 were characterized by FT-IR, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and atomic absorption spectroscopy. Compound 2 is further analyzed by nitrogen adsorption/desorption technique. The obtained coordination compounds were employed as heterogeneous catalysts for selective oxidation of benzyl alcohol to benzoic acid using CH2Cl2 as solvent and tert-butyl hydroperoxide (TBHP) as oxidant. The catalysts displayed good activity in the oxidation reaction and could be reused without noticeable loss of activity.

Thermal control of the defunctionalization of supported Au25(glutathione)18 catalysts for benzyl alcohol oxidation.

Au25(SG)18 (SG – glutathione) clusters deposited on ZrO2 nanoparticles have been used as a catalyst for benzyl alcohol oxidation. Calcination was performed at different temperatures to study the ligand and particle size effect on the catalytic activity. In contrast to most gold nanoclusters which have to be completely defunctionalized for maximum catalytic activity, the partially defunctionalized Au25(SG)18@ZrO2 catalyst, thermally treated at 300 °C, exhibits full conversion of benzyl alcohol within 15 h under atmospheric pressure with 94% selectivity towards benzaldehyde.

Nanosized samarium modified Au-Ce0.5Zr0.5O2 catalysts for oxidation of benzyl alcohol

In this study, Au-Ce0.5Zr0.5O2 (Au-CeZr) and Sm modified AuCeZr catalysts were synthesized by organic deposition-precipitation method using gold acetate and samarium acetate as Au and Sm precursors and tetrapropyl ammonium hydroxide as precipitating agent. The synthesized nanocrystalline Au-CeZr and Sm modified Au-CeZr materials found be effective catalysts for benzyl alcohol oxidation at low reaction temperatures. The catalysts were characterized by XRD, SEM, TEM, DRIFT spectra after pyridine adsorption, N2-physisorption, XPS and H2-TPR techniques. The Au nanoparticles are highly dispersed on CeZr support and XRD reflections due to presence of Au metal were not observed for the samples which contained less than 1.0 wt% Au. The XPS and H2-TPR results revealed that at lower Au loadings, strong Au-CeZr interaction resulted an easy exclusion of surface oxygen ions in Au-CeZr and Sm-Au-CeZr catalysts. Pyridine adsorption results indicated an increase of Lewis acid sites of the CeZr support after Au deposition and Sm modification. The 2.0Sm-0.5Au-CeZr catalyst is most active and selective catalysts for benzyl alcohol oxidation among the synthesized catalysts due to optimum loading of Au and Sm. An optimal surface acidity and redox properties is accountable for the improved catalytic activity of 2.0Sm-0.5Au-CeZr catalyst in the benzyl alcohol oxidation.

Zeolite Y encapsulated Cu (II) and Zn (II)-imidazole-salen catalysts for benzyl alcohol oxidation

To mimic biological enzyme in catalysis, metal-imidazole-salen complexes were proposed (via DFT calculation) and synthesized in situ within the cavities of Y zeolite. Among the synthesized zeozymes, the Cu-salenIIY exhibited a prominent catalytic efficiency for the selective oxidation of benzyl alcohol. Specifically, the activity and selectivity of the encapsulated catalyst were comparable to those of the free Cu-salenII complex in solution. Furthermore, the high activity and selectivity were preserved during the repeated cycles. The similarity in the initial activity implies that the Cu-salenII complex just resides in the cavity of the zeolite Y, and its intrinsic properties responsible for the catalytic activity keep intact after encapsulation. The confinement of zeolite nanocavities effectively inhibited the dimerization or aggregation of the Cu-salenII complex and prevented the active species from escaping into reaction solution, thus resulting in a remarkably improved in the catalytic reusability and durability.

Pd–P nanoalloys supported on a porous carbon frame as an efficient catalyst for benzyl alcohol oxidation

A 3D carbon frame (PCF) acted as a support for Pd–P nanoalloys and was used as an efficient catalyst for benzyl alcohol oxidation.

A Structurally Characterized CuIII Complex Supported by a Bis(anilido) Ligand and Its Oxidative Catalytic Activity.

Three copper(II) complexes of the (R,R)-N,N'-bis(3,5-di-tert-butyl-2-aminobenzylidene)-1,2-diaminocyclohexane ligand, namely [Cu(N L)], [Cu(N LH)]+ and [Cu(N LH2 )]2+ , were prepared and structurally characterized. In [Cu(N LH2 )]2+ the copper ion lies in an octahedral geometry with the aniline groups coordinated in equatorial positions. In [Cu(N L)] the anilines are deprotonated (anilido moieties) and coordinated to an almost square-planar metal ion. Complex [Cu(N L)] displays two oxidation waves at E1/2ox, 1 =-0.14 V and E1/2ox, 2 =0.36 V vs. Fc+ /Fc in CH2 Cl2 . Complex [Cu(N LH2 )]2+ displays an irreversible oxidation wave at high potential (1.21 V), but shows a readily accessible and reversible metal-centered reduction at E1/2red =-0.67 V (CuII /CuI redox couple). Oxidation of [Cu(N L)] by AgSbF6 produces [Cu(N L)](SbF6 ), which was isolated as single crystals. X-ray structure analysis discloses a contraction of the coordination sphere by 0.05 Å upon oxidation, supporting a metal-centered process. Complex [Cu(N L)](SbF6 ) displays an intense NIR band at 1260 nm corresponding to an anilido-to-copper(III) charge transfer transition. This compound slowly evolves in CH2 Cl2 solution towards [Cu(N LH)](SbF6 ), which is a copper(II) complex comprised of both anilido and aniline groups coordinated to the metal center. The copper(III) complex [Cu(N L)](SbF6 ) is an efficient catalyst for benzyl alcohol oxidation, with 236 TON in 24 h at 298 K, without additives other than oxygen and a base.

A Liquid Derivative of Phosphotungstic Acid as Catalyst for Benzyl Alcohol Oxidation in Water: Facile Separation and Stability of Benzaldehyde at Room Temperature†

AbstractPolyetheramines belong to a class of green di‐block copolymer with ethylene oxide and propylene oxide moieties along with terminal amine functionality. The polymers are biocompatible and show temperature dependant phase separation properties. Herein, we report the effect of a polyetheramine (Jeffamine®) on the catalytic properties of a well studied polyoxometalate catalysts, phosphotungstic acid (PTA). The catalytic reaction chosen for the test is the hydrogen peroxide‐mediated oxidation of benzyl alcohol (BzOH). Modification of PTA with Jeffamine® (PTA‐Jeffamine®) resulted in a solvent‐less liquid‐like material accessible to a wide range of solvents. The PTA‐Jeffamine® catalyst was observed to enhance the conversion of BzOH compared to that of pristine PTA and facilitated easy separation of benzaldehyde (BzH) and catalyst from reaction mixture. Stability of synthesized BzH was studied with gas chromatography attached with mass spectrometry (GC‐MS). Synthesis of the catalyst is cost‐effective and scalable due to easy availability of the individual components and nature of the synthetic protocol. UV‐visible spectroscopy, Fourier transform infrared spectroscopy (FT‐IR) and field emission scanning electron microscopy (FE‐SEM) were used to characterize the catalyst. Surface tension experiment, FE‐SEM, ICP‐MS and controlled experiments were performed to understand the effect of Jeffamine® in the catalytic process.

Gold nanoparticle-decorated halloysite nanotubes – Selective catalysts for benzyl alcohol oxidation

Preparation of gold nanoparticle-decorated halloysite nanotubes (Au-Hal) by a deposition method and evaluation of their catalytic activity in an oxidation of benzyl alcohol are reported. An electrostatic attraction between positively charged polyethylenimine (PEI)-capped gold nanoparticles and the negatively charged external surfaces of halloysite nanotubes (Hal nanotubes) was the key factor in fabrication of Au-Hal nanotubes. Au-Hal catalysts showed good conversions and surprisingly high benzaldehyde selectivities (above 90%) in the benzyl alcohol oxidation. Influence of the amount of PEI used as a capping agent, the gold content and calcination of Au-Hal catalysts on the conversion and selectivity was investigated. A notable increase in the benzaldehyde selectivity at higher PEI contents and a significant drop in the benzaldehyde selectivity on calcination clearly indicate the central role of PEI in the selective formation of benzaldehyde. The high benzaldehyde selectivity of uncalcined catalysts are probably due to PEI donor molecules coordinating to certain surface sites on Au nanoparticles and thus blocking the catalytic sites required for further oxidation of benzaldehyde to benzoic acid. The high combined selectivity of benzoic acid and benzyl benzoate obtained with the calcined catalysts indicates that naked gold nanoparticles have the catalytic sites available for the benzoic acid formation.

Influence of pretreatment atmospheres on the performance of bimetallic Au-Pd supported on ceria-zirconia mixed oxide catalysts for benzyl alcohol oxidation

Monometallic Au, Pd and bimetallic Au-Pd catalysts supported on a Ce0.62Zr0.38O2 mixed oxide have been synthesized by the sol-immobilization method. An in-depth Scanning-Transmission Electron Microscopy (STEM) study has been performed to reveal the structural and chemical nature of the metal nanoparticle system present in these catalysts. Attention has been paid both to the evolution of the particle size distribution and the degree of Au-Pd interaction as a function of the treatment used to activate the catalysts. This characterization work has been complemented by results coming from other macroscopic techniques like Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), N2 physisorption, Temperature Programmed Oxidation (TPO) or X-ray Photoelectron Spectroscopy (XPS). The whole set of characterization data evidences the intrinsic structural complexity of this type of bimetallic systems, in which a fraction of monometallic Au, monometallic Pd and bimetallic nanoparticles of varying compositions coexist. This picture, which clearly contrasts with other much more homogeneous situations described in previous literature on bimetallic catalysts, also indicates the requirement of combining both atomic scale and macroscopic techniques to understand the structure of these catalysts.Concerning catalytic performance, a synergistic effect between Au and Pd has been observed in the selective oxidation of benzyl alcohol on ceria-zirconia. Moreover, the catalytic activity of these bimetallic Au-Pd catalysts is higher than that on other commonly used supports, such as activated carbon or carbon nanotubes. The treatments in oxidative and inert atmospheres at 250°C improve the catalytic activity with respect to the fresh, un-pretreated, catalyst. Subsequent reduction of the oxidized bimetallic catalyst leads to an activity similar to that of the fresh catalyst, which is reduced at room temperature with H2 bubbles.

Bio-molecule assisted aggregation of ZnWO4 nanoparticles (NPs) into chain-like assemblies: material for high performance supercapacitor and as catalyst for benzyl alcohol oxidation.

ZnWO4 nanoparticles (NPs) that are assembled and aggregated together as chain-like morphology have been synthesized via the reaction of Zn(II) salt solution with sodium tungstate in the presence of the DNA scaffold under 5 min of microwave heating. The reaction parameters have been tuned to control the size of the individual particles and diameter of the chains. The significance of different reaction parameters and specific growth mechanism for the formation of particles is elaborated. The DNA-ZnWO4 nanoassemblies have been used in two potential applications for the first time, namely, supercapacitor and catalysis studies. Supercapacitor study revealed that DNA-ZnWO4 nanoassemblies exhibited good electrochemical properties having high specific capacitance value ∼72 F/g at 5 mV s(-1), and electrodes possessed a good cyclic stability with more than 1000 consecutive times of cycling. Catalysis studies have been done for benzyl alcohol oxidation, and it was observed that DNA-ZnWO4 nanoassemblies having smaller diameter gives better catalytic efficiency compared to other morphology. This is further authenticated from their BET surface area analysis. In the future, the self-assembled DNA-ZnWO4 nanoassemblies could be a promising candidate for the synthesis of other mixed metal oxides and should be applicable in various emerging fields like Li ion batteries or photocatalysis, or as luminescent materials.

Mn(Salen)Cl complexes immobilized on SBA-15 functionalized with amine as an efficient, selective and recyclable catalyst for benzyl alcohol oxidation by TBHP: the effects of Mn loading and reaction conditions

In this work, SBA-15 molecular sieves were functionalized with propylamine. A series of Mn(Salen)Cl complexes immobilized on amine functionalized SBA-15 (SBA-15-pr-NH2) with different loading of Mn in range of 0.293–0.765 mmol Mn/g catalyst were prepared. These samples were characterized by BET, XRD, TGA–DSC, UV–Vis and FT-IR. The catalytic activity of immobilized Mn(Salen)Cl complexes was evaluated in the oxidation of benzyl alcohol in the liquid phase using tert-butylhydroperoxide (TBHP) as the oxidant. It was found that Mn(Salen) complexes immobilized on the SBA-15-pr-NH2 are an efficient catalyst for the oxidation of benzyl alcohol and showed high catalytic activity and selectivity to benzaldehyde. As we expected, the leaching of manganese complexes from the support during the reaction was negligible, because of strong interaction between Mn(Salen)Cl complexes and the amine groups on the surface. The effects of Mn loading and various solvents on the conversion and selectivity were studied. A second order function for the variation in catalytic activity with respect to the loading of Mn(Salen)Cl in different catalyst samples was observed. The activity of the SBA-15-pr-Mn(Salen)Cl catalyst differs with the type of the solvent, and, in this case, acetonitrile gives the best conversion results. The influences of reaction temperature, reaction time, solvent, reusability, amount of catalyst and TBHP to benzyl alcohol molar ratio were investigated. Under optimized conditions, 73.5 % conversion of benzyl alcohol and 100 % selectivity to benzaldehyde was achieved.

Single-step co-deposition of nanostructured tungsten oxide supported gold nanoparticles using a gold–phosphine cluster complex as the gold precursor

The use of a molecular gold organometallic cluster in chemical vapour deposition is reported, and it is utilized, together with a tungsten oxide precursor, for the single-step co-deposition of (nanostructured) tungsten oxide supported gold nanoparticles (NPs). The deposited gold-NP and tungsten oxide supported gold-NP are highly active catalysts for benzyl alcohol oxidation; both show higher activity than SiO2 supported gold-NP synthesized via a solution-phase method, and tungsten oxide supported gold-NP show excellent selectivity for conversion to benzaldehyde.

Sm-CeO2 supported gold nanoparticle catalyst for benzyl alcohol oxidation using molecular O2

Supported gold nanoparticles perform as a potential catalyst for CO oxidation, propylene epoxidation and hydrogenation reactions, while using them for alcohol oxidation reaction in the presence of molecular oxygen is a challenging task. Nanocrystalline ceria supported gold catalysts are suitable candidates for alcohol oxidation reaction under mild condition. In this study, ceria based mixed oxides were prepared by modified sol–gel method using triethanolamine/water mixture where the defect sites were created by doping Sm3+ cation to cerium oxide. The catalysts were characterized by XRD, FT-RAMAN, TPR, TPD, XPS, XAFS, and HRTEM techniques. Strong gold–support interaction facilitates the easy removal of capping oxygen ions present in the Sm3+ doped cerium oxide surface as observed by XPS and TPR studies. The acid–base property of the CeO2 oxide after incorporation of samarium and gold deposition was observed from TPD studies. The Au/Sm-CeO2 catalyst was active for benzyl alcohol oxidation reaction using molecular O2 under mild condition.