Au Pd Bimetallic Catalysts Research Articles

Understanding the Nature of Amino Acid Interactions with Pd(111) or Pd-Au Bimetallic Catalysts in the Aqueous Phase.

The interaction of methionine (Met) with different bimetallic-segregated surfaces comprising a uniform distribution of strips and islands of Au on the Pd(111) surface was examined using molecular dynamics (MD) simulations. Out of all the segregated and uniformly doped surfaces studied, the design of Pd-Au islands showed some reduction in the interaction energy (Eint = -43.7 kJ/mol) as compared to that of the pure Pd(111) surface (Eint = -50 kJ/mol) for a single Met molecule. However, at a higher coverage of 9 Met molecules/simulation cell, none of the Pd-Au alloy surfaces showed any improvement as compared to the Pd(111) surface. In order to develop a comprehensive understanding of the nature of the nonbonded interaction of aqueous biogenic impurities with the Pd catalyst surface, the MD study was extended to include a variety of aliphatic, S-containing, aromatic, and polar amino acids. The potential of mean force (PMF) profiles were observed to be distinct for each class of amino acids with substantial differences among amino acids with acidic and basic side chains. The side chains of all the polar and aromatic amino acids showed direct contact with the surface while aliphatic amino acids had their hydrophobic side chain aligned away from the surface. Interestingly, lysine (Lys) and tyrosine (Tyr) were the only two amino acids which interacted preferentially via the distant backbone nitrogen and backbone oxygen, respectively, despite their side chains being in direct contact with the metal surface. The strength of interaction was correlated with the size of the amino acid; the interaction energies were observed to be the maximum for large molecules such as arginine (Arg, Eint = -87.7 kJ/mol) and tryptophan (Trp, Eint = -73.4 kJ/mol), while it was a minimum for aliphatic amino acids such as alanine (Ala, Eint = -10.9 kJ/mol). The study is focused on examining the sensitivity of the choice of the preferential interaction site, conformational preferences, and interaction energies to the side-chain specificity.

Tuning Pd–Au Bimetallic Catalysts for Heterogeneous Parahydrogen-Induced Polarization

The heterogeneous hydrogenation of propene over supported Pd–Au bimetallic nanoparticles was investigated using NMR and the parahydrogen-induced polarization (PHIP) technique. The composition and structure of Pd–Au/TiO2 catalysts were correlated to both catalytic activity and pairwise hydrogen addition. Sol-immobilization, impregnation, and deposition–precipitation methods were used for preparation of the Pd–Au bimetallic catalysts. A strong signal enhancement was observed on the bimetallic catalyst prepared through the sol-immobilization method, up to 24-fold higher than that with the other two methods. The polyvinyl alcohol (PVA) stabilizer bound to the metal surface was responsible for the enhanced PHIP effect. The removal of the PVA ligands by water washing and calcination treatments shows a significant effect on the hydrogen pairwise addition. Increasing the Au content in the bimetallic alloy led to a promotion of the pairwise selectivity due to the ensemble effect. The pairwise selectivity could be tuned by the morphologies of Pd–Au structures; the Au-shell/Pd-core morphology produced a higher pairwise selectivity than that of the Pd-shell/Au-core structure, while the random PdAu alloy showed the best PHIP effect.

Novel blended catalysts consisting of a TiO2 photocatalyst and an Al2O3 supported Pd-Au bimetallic catalyst for direct dehydrogenative cross-coupling between arenes and tetrahydrofuran.

Dehydrogenative cross-coupling (DCC) is a clean methodology to make C–C bonds by using abundant C–H bonds. The blended catalyst, developed in this study, consists of a TiO2 photocatalyst and an Al2O3 supported Pd–Au bimetallic catalyst and shows superior activity to the conventional TiO2 photocatalyst loaded with the corresponding metal co-catalyst for the direct DCC between various arenes and tetrahydrofuran, with concomitant evolution of hydrogen gas. The reactions were done under mild conditions without consuming any oxidising agent or other additional chemicals. This new approach of separating the photocatalyst and the metal catalyst parts allows their independent modification to improve the overall catalytic performance.

Photocatalytic Ullmann coupling of aryl halides by a novel blended catalyst consisting of a TiO2 photocatalyst and an Al2O3 supported Pd–Au bimetallic catalyst

Synergy of TiO2 photocatalyst and Pd–Au bimetallic nanoparticles is essential for the efficient photocatalytic Ullmann coupling of aryl halides.

A hierarchical flower-like hollow alumina supported bimetallic AuPd nanoparticle catalyst for enhanced solvent-free ethylbenzene oxidation.

Currently, oxidation of alkylaromatics is considered as one of the most crucial chemical technologies to produce high added-value alcohols, ketones and carboxylic acids, due to its significant importance both in fine synthetic chemistry and in the academic field. In this work, a novel hierarchical marigold-like hollow alumina supported bimetallic AuPd nanoparticle catalyst was successfully fabricated and employed for highly efficient solvent-free ethylbenzene oxidation to produce acetophenone with the coexistence of both molecular oxygen and tert-butyl hydroperoxide as the oxidant and the initiator. The as-fabricated bimetallic AuPd nanocatalyst conferred a superior catalytic performance to the corresponding monometallic counterparts and commercial Al2O3 or solid Al2O3 microsphere supported AuPd ones, along with a high acetophenone selectivity of 88.2% at a conversion of 50.9% under mild reaction conditions (120 °C and oxygen pressure of 1.0 MPa), as well as an unprecedentedly high turnover frequency value of 46 768 h-1. Such exceptional efficiency of the catalyst was related to both the significant synergy between the Au-Pd atoms and strong metal-support interactions, and the unique hierarchical micro/nanostructure of the support being beneficial to the close contact of reactants with surface adsorption and reaction sites and easy product diffusion. Moreover, the present bimetallic AuPd catalyst was recyclable and stable. The developed approach is expected to offer exciting opportunities for designing other supported monometallic or bimetallic catalysts with various active components applied in heterogeneous catalysis.

Fingerprint Feature of Atomic Intermixing in Supported AuPd Nanocatalysts Probed by X-ray Absorption Fine Structure

We report on a systematic study of AuPd bimetallic nanoparticles (NPs) prepared from two-step sputtering deposition in the suspension of graphene and ionic liquid using X-ray absorption fine structure (XAFS) spectroscopy. As-synthesized AuPd bimetallic catalysts possess well-enhanced activity and stability compared with monometallic (Au-only or Pd-only) catalysts, suggesting the synergistic effect upon alloying. A structural model with the introduction of Pd to Au cluster is provided to study the formation of bimetallic NPs and to offer detailed insights into the local structure information (interaction between Au and Pd). A novel and significant fingerprint is proposed to depict the intermixing structure of AuPd bimetallic NPs. The present XAFS study reveals a fingerprint feature in k-space, which can be an evaluation of the extent of the Au–Pd intermixing on the atomic scale, corresponding to the catalytic activity of bimetallic nanoparticles. The systematic XAFS-based methodology, demonstrated here on ...

Direct synthesis of H2O2 on Pd and AuxPd1 clusters: Understanding the effects of alloying Pd with Au

Direct synthesis (H2 + O2 → H2O2) could produce H2O2 (an environmentally benign oxidant) more cost-effectively and sustainably than anthraquinone oxidation, enabling broader use of H2O2 for industrial oxidations. We examine direct synthesis on AuxPd1 clusters to better understand the reasons for the high H2O2 selectivities of these materials. Steady-state H2O2 and H2O formation rates were measured as functions of reactant pressure, temperature, and the protic or aprotic nature of the solvent. The analysis of these measurements indicates that H2O2 forms by consecutive proton-electron transfer steps on AuxPd bimetallic catalysts. Among similarly sized Pd and AuxPd1 catalysts, increases in the Au:Pd ratio lead to simultaneous but unequal increases in the activation enthalpies (ΔH‡) for both H2O2 and H2O formation, which must result from significant electronic changes to Pd by Au. Detailed comparisons of these changes in ΔH‡ for H2O2 and H2O production to H2O2 selectivities provide compelling evidence that these electronic effects are primarily responsible for the high H2O2 selectivities commonly reported on AuPd bimetallic catalysts. Additionally, these results lack any clear trends that suggest ensemble effects contribute to the increased preference to form H2O2 on AuPd bimetallics within the ranges of compositions typically reported. These findings provide useful information on the significance of electronic effects in these AuxPd1 clusters and may guide the design of increasingly selective bimetallic catalysts.

Conversion of Ethanol into a Fraction of C3+ Hydrocarbons in the Presence of Gold-Containing Catalysts Based on a Zeolite MFI Support

The results of a study on the activity and operational stability of an Au–Pd/MFI/Al2O3 catalyst in the reaction of ethanol conversion into a gasoline fraction of hydrocarbons are reported. In the presence of the Au–Pd/MFI/Al2O3 catalyst, ethanol was almost completely converted into an alkane–aromatic fraction of C3–C11 hydrocarbons at 300°C in an atmosphere of Ar; the yield of this fraction was as high as 90% on a feed carbon basis. It was established that, in the presence of the bimetallic Au–Pd catalyst, the yield of the target fraction increased by 10%, as compared with that on a monometallic Au-containing sample. The Au–Pd/MFI/Al2O3 catalyst exhibited much higher stability in a long-term experiment in comparison with the previously tested pilot sample of Pd–Zn/MFI/Al2O3. After a 40-h operation, the yield of the target fraction of C3+ hydrocarbons in the presence of the Au–Pd/MFI/Al2O3 catalyst decreased by 15%. The treatment of the catalyst with hydrogen led to the complete restoration of its activity. The structure of the Au–Pd active constituents was studied by transmission electron microscopy X-ray photoelectron spectroscopy. methods of the and microscopy.

Gold–Palladium Bimetallic Catalyst Stability: Consequences for Hydrogen Peroxide Selectivity

During application, electrocatalysts are exposed to harsh electrochemical conditions, which can induce degradation. This work addresses the degradation of AuPd bimetallic catalysts used for the electrocatalytic production of hydrogen peroxide (H2O2) by the oxygen reduction reaction (ORR). Potential-dependent changes in the AuPd surface composition occur because the two metals have different dissolution onset potentials, resulting in catalyst dealloying. Using a scanning flow cell (SFC) with an inductively coupled plasma mass spectrometer (ICP-MS), simultaneous Pd and/or Au dissolution can be observed. Thereafter, three accelerated degradation protocols (ADPs), simulating different dissolution regimes, are employed to study the catalyst structure degradation on the nanoscale with identical location (IL) TEM. When only Pd or both Au and Pd dissolve, the composition changes rapidly and the surface becomes enriched with Au, as observed by cyclic voltammetry and elemental mapping. Such changes are mirrored by ...

Aerobic Oxidation of Glucose to Glucaric Acid under Alkaline-Free Conditions: Au-Based Bimetallic Catalysts and the Effect of Residues in a Hemicellulose Hydrolysate

Au–Pt and Au–Pd bimetallic catalysts were prepared over various supports using different preparation methods and were compared in the base-free selective aerobic catalytic oxidation of glucose to glucaric acid. The method of preparation of the bimetallic catalysts, the support material for the Au–Pt bimetallic nanoparticles, and the metal molar ratios have a strong influence on the activity and the maximum yield of glucaric acid. The Au–Pt/ZrO2 catalyst with a molar ratio for Au/Pt = 1 provides a 50% yield of glucaric acid at complete conversion of glucose and gluconic acid at 100 °C, under 40 bar air, using a glucose/metal ratio of 80. The catalyst was stable upon sequential recycling in a batch reactor and in long-term use in a continuous reactor. The influence of possible residual impurities has been studied. Furan derivatives or lignin residues might be problematic for catalytic oxidation of glucose in hemicellulose hydrolysates.

Investigation of Polyaniline-Supported Au-Pd Bimetallic Catalysts for Propanol Oxidation Reactions in Alkaline Media

Polyaniline (PANI) is extensively studied due to its unique electrochemical properties. Its conjugated structure makes PANI highly conductive. This conductivity can be fine-tuned by changing the electrolyte used for polymerization or the pH of its environment1. With a high chemical stability below 100°C, mechanical strength, and large surface area, the applications of PANI are numerous – from chemical sensing to corrosion inhibition coatings to light emitting diodes2. Another application for PANI is its use as a substrate for catalysts. Previous work has thoroughly investigated the electrochemical polymerization of PANI, electrochemical insertion of Pd and Au into PANI to form PANI/Pd3 and PANI/Au4composites, and the resulting composites’ catalytic activities for alcohol oxidation. Unfortunately, each of these composites has shown a significant amount of surface poisoning during alcohol oxidation, reducing its viability as an efficient catalyst. In an effort to reduce surface poisoning, scientists have been examining the effects of adding a second metal to well-known, commonly-used catalysts. These bimetallic catalysts have been shown to reduce surface poisoning and increase catalytic activity. One possible explanation for this phenomenon is an electronic effect - the interaction of the two metals causes a shift in the electronic structure of the catalyst’s surface, resulting in a weakened interaction with poisoning species5. Another possibility is that it is due to a bifunctional effect. In one case different metals adhere to different functional groups in the molecule allowing for a more stable transition state and thus more efficient catalysis6. In the case of oxidation in alkaline media, hydroxide groups from the solvent adsorb to the secondary metal, then react with poisoning species on the primary catalytic metal to form molecules that are more easily removed from the catalyst surface7. Most likely some combination of these three phenomena results in reduced poisoning and increased efficiency. This presentation will expand PANI research into the area of bimetallic PANI composites, specifically focusing on the simultaneous deposition of Au and Pd into PANI films. Three composites were prepared, each using a metal precursor solution with a different Au to Pd molar ratio (1:1, 2:1, or 1:2). Electrochemical data from metal deposition, surface oxide formation and reduction, and oxidation of 1-propanol provide insights into how metals interact with each other and their environment within the polymer. SEM/EDX data show morphology and composition of the composites. Overall the bimetallic composites show reduced surface poisoning and increased catalytic efficiency in comparison to their monometallic counterparts. References (1) D. W. Hatchett, M. Josowicz, and J. Janata, J. Phys. Chem. B103 (1999) 10992-10998. (2) A. A. Syed and M. K. Dinesan, Talanta38 (1991) 815-837. (3) D. W. Hatchett, N. M. Millick, J. M. Kinyanjui, S. Pookpanratana, M. Bär, T. Hofmann, A. Luinetti, and C. Heske, Electrochim. Acta56 (2011) 6060-6070. (4) D. W. Hatchett, M. Josowicz, J. Janata, and D. R. Baer, Chem. Mater.11 (1999) 2989-2994. (5) A. A. Rodriguez, C. T. Williams, and J. R. Monnier, Appl. Catal. A475 (2014) 161-168. (6) A. A. Rodriguez, C. T. Williams, and J. R. Monnier, Catal. Lett.145 (2015) 750-756. (7) X. Wang, B. Tang, X. Huang, Y. Ma, and Z. Zhang, J. Alloys Compd. 565 (2013) 120-126.

N-Formylation of Amines with CO2 and H2 Using Pd–Au Bimetallic Catalysts Supported on Polyaniline-Functionalized Carbon Nanotubes

Bimetallic Pd–Au catalyst was prepared by depositing the Pd–Au alloy nanoparticles on polyaniline-functionalized carbon nanotubes (PANI-CNT) and the resulting Pd–Au/PANI-CNT catalyst exhibited excellent catalytic activity for the N-formylation of pyrrolidine using CO2/H2. The structural and electronic properties of the Pd–Au/PANI-CNT was characterized by X-ray powder diffraction (XRD), nitrogen adsorption–desorption, transmission electron microscopy (TEM), high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and X-ray photoelectron spectroscopy (XPS). Under optimized conditions, an N-formylpyrrolidine yield of 98.3% was obtained from pyrrolidine and CO2/H2 at 125 °C by using Pd–Au/PANI-CNT with a Pd/Au molar ratio of 1:1. Our research further reveals that Pd atoms should be the true active sites for the hydrogenation reaction and the N-formylation reaction might occur mainly over Pd atoms or over the interface between Pd atoms and Au atoms for the bimetallic Pd–Au/PANI-CNT...

Aerobic oxidative esterification of primary alcohols over Pd-Au bimetallic catalysts supported on mesoporous silica nanoparticles

We have prepared a series of mesoporous silica nanoparticle (MSN) supported Pd-Au bimetallic catalysts using a newly developed sequential impregnation method. These catalysts were fully characterized by various techniques including nitrogen sorption, powder X-ray diffraction, inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM) and high angle annular dark-field scanning transmission electron microscopy (HADDF-STEM). By using this synthetic approach, we observed metal nanoparticles (NP) with diameters of 1–2nm homogeneously supported on the MSN. The catalytic performance of these MSN supported metal NPs was tested by aerobic oxidative esterification in a tandem reaction where primary alcohols are oxidized to their corresponding aldehydes and to esters in a subsequent reaction. We determined that Pd NPs are very efficient in the first step of oxidation; however, stagnant in the subsequent oxidation. On the contrary, Au NPs show slow reactivity in converting alcohols to aldehydes, but extraordinarily efficient in the oxidation of aldehydes to esters. By fine tuning the metal ratio, the bimetallic catalyst exhibits better reactivity and selectivity toward a variety of primary alcohols than the corresponding monometallic catalysts. In addition, we also found that the bimetallic Pd-Au@MSN catalysts can be recycled three times without a significant loss in activity.

Tuning chemical compositions of bimetallic AuPd catalysts for selective catalytic hydrogenation of halogenated quinolines

Au1−xPdx bimetallic catalysts with low Pd entities on CeO2 nanorods delivered high activity and chemoselectivity for hydrogenation of halogenated quinolines. Improved chemoselectivity could be attributed to the selective adsorption configurations of halogenated quinolines on Au via tilted orientation rather than on Pd via flat orientation.

Gold on carbon and titanium oxides composites: Highly efficient and stable acetylene hydrogenation in large excess of ethylene

Photocatalytically generated gold on carbon and TiO2 composites were used for acetylene hydrogenation in excess ethylene, in a way close to current industrial practices. The crystalline effect of TiO2 and the addition of Pd to supported Au catalysts on acetylene hydrogenation were investigated. Carbon and amorphous TiO2 supported Au were highly active, selective, and stable and possessed the highest ethylene yield of 83% at 210°C with a H2/C2H2 ratio of 2/1 for selective hydrogenation of acetylene to ethylene. With further addition of Pd to the supported Au catalyst, ethylene yield reached a maximum value of 57% at 30°C with a H2/C2H2 ratio of 2/1. The enhanced performance originated from small neutral Au nanoparticles and the formation of bimetallic Au–Pd catalyst. This report opens up promising possibilities for the design of highly efficient heterogeneous supported gold catalysts.

Synergy and Anti-Synergy between Palladium and Gold in Nanoparticles Dispersed on a Reducible Support.

Highly active and stable bimetallic Au–Pd catalysts have been extensively studied for several liquid-phase oxidation reactions in recent years, but there are far fewer reports on the use of these catalysts for low-temperature gas-phase reactions. Here we initially established the presence of a synergistic effect in a range of bimetallic Au–Pd/CeZrO4 catalysts, by measuring their activity for selective oxidation of benzyl alcohol. The catalysts were then evaluated for low-temperature WGS, CO oxidation, and formic acid decomposition, all of which are believed to be mechanistically related. A strong anti-synergy between Au and Pd was observed for these reactions, whereby the introduction of Pd to a monometallic Au catalyst resulted in a significant decrease in catalytic activity. Furthermore, monometallic Pd was more active than Pd-rich bimetallic catalysts. The nature of the anti-synergy was probed by several ex situ techniques, which all indicated a growth in metal nanoparticle size with Pd addition. However, the most definitive information was provided by in situ CO-DRIFTS, in which CO adsorption associated with interfacial sites was found to vary with the molar ratio of the metals and could be correlated with the catalytic activity of each reaction. As a similar correlation was observed between activity and the presence of Au0* (as detected by XPS), it is proposed that peripheral Au0* species form part of the active centers in the most active catalysts for the three gas-phase reactions. In contrast, the active sites for the selective oxidation of benzyl alcohol are generally thought to be electronically modified gold atoms at the surface of the nanoparticles.

ChemInform Abstract: Shape‐Controlled Synthesis of Au—Pd Bimetallic Nanocrystals for Catalytic Applications

AbstractReview: 111 refs.

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.

Bimetallic Au-decorated Pd catalyst for the liquid phase hydrodechlorination of 2,4-dichlorophenol

Monometallic and bimetallic Pd-Au catalysts supported on multi-walled carbon nanotubes (CNTs) with varied Au cooperation amounts were prepared using the complexing-reduction method in the presence of tetrahydrofuran (THF). The liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenol (2,4-DCP) was investigated over these bimetallic catalysts. The catalysts were characterized by N2 adsorption-desorption isotherms, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and H2 chemisorption. Characterization results showed that the co-reduction of Pd and Au mainly formed alloy-like structure. The bimetallic catalysts had smaller metal particles and larger numbers of exposed active site than that of monometallic catalysts. In addition, compared with Pd(1.7)/CNTs and Au(0.4)/CNTs, the binding energies of Pd 3d5/2 shifted to higher positions while that of Au 4f7/2 had negative shifts in the Pd-Au bimetallic catalysts, which can be ascribed to the electrons transferred from metal Pd to Au and the cationization of Pd particles was enhanced. Accordingly, the bimetallic Pd-Au particles with different Au contents in the catalysts exhibited varied synergistic effects for the catalytic HDC of 2,4-DCP, with Pd(1.8)Au(0.4)/CNTs having the highest catalytic activity. For the bimetallic catalysts, a disproportional increase of turnover frequency (TOF) was observed with increasing Au content due to the enhanced cationization of Pd particles. Moreover, the dechlorination of 2,4-DCP over the supported monometallic and bimetallic catalysts proceeded via both the stepwise and concerted pathway, and the concerted pathway became predominant with Au decoration amount in the catalyst.

Synergistic effect of bimetallic Au-Pd supported on ceria-zirconia mixed oxide catalysts for selective oxidation of glycerol

A series of bimetallic Au-Pd catalysts supported on Ce0.62Zr0.38O2 mixed oxide has been synthesized using a simultaneous deposition-precipitation method. Different Au:Pd ratios were obtained maintaining Au loadings constant and varying Pd content. Elemental analysis, X-ray diffraction, N2 physisorption, X-ray photoelectron spectroscopy, scanning transmission electron microscopy-high angle annular dark field (STEM-HAADF) and X-ray energy dispersive spectroscopy (XEDS) techniques have been employed to characterize these catalysts. The catalytic activities for selective oxidation of glycerol over these bimetallic catalysts have been evaluated, a synergistic effect being observed. Thus, the bimetallic Au-Pd catalyst with the lowest Pd content was the one exhibiting the highest catalytic activity among all the prepared catalysts. Oxidation at 700°C of the bimetallic 2.2AuPd/Ce0.62Zr0.38O2 catalyst led to an increase of the catalytic activity for the selective oxidation of glycerol, which seemed to be due to the formation of a larger fraction of bimetallic Au-Pd alloy-type nanoparticles after oxidation at higher temperatures.