X-ray Absorption Spectroscopy Techniques Research Articles

Atomic structure of gold nanoparticles stabilized in polyethylene

Transmission electron microscopy, X-ray powder diffraction, and X-ray absorption spectroscopy techniques were used to study the atomic structure of gold nanoparticles involving 1, 5, 10, and 20 wt % of Au which were stabilized in a high-pressure polyethylene matrix. The average sizes of the Au-containing nanoparticles amounted to 7 and 50 nm. The atomic structure of the Au-containing nanoparticles was similar to that of metallic gold in the bulk state. When the Au concentration in polyethylene was equal to 1 wt %, gold atoms were found on the surface of nanoparticles, which interacted with light atoms C/O.

MeV ion exposure behaviour of PMMA resist polymer studied by synchrotron light spectroscopies

The behaviour of poly-(methyl methacrylate) (PMMA) resist exposed with 2MeV 1H+ and 6MeV 12C3+ ions has been investigated by using the photo-electron spectroscopy (PES) and X-ray absorption spectroscopy (XAS) techniques. Preliminary PES results were difficult to analyse without special precautions to counteract surface charging. XAS was on the other hand almost insensitive to the effects of surface charging. XAS investigations of the bonding in the near surface and deeper in PMMA revealed significant changes of the bonding of carbon atoms at fluences correspond to clearing (positive resist mode) and cross-linking (negative resist mode). In the clearing fluence regime the CC bonds increase in the surface and at greater depths which is consistent with our earlier work with Raman spectroscopy. In the high fluence regime where cross-linking takes place, a reduction of C–O and CO bonding is seen which might be indicative that the cross linking is associated with side-chain scission.

Structure, characterization, and magnetic/electrochemical properties of Ni-doped BiFeO3 nanoparticles5

The BiFe1−xNixO3 (x = 0, 0.05, 0.1, 0.2, and 0.3) nanoparticles were prepared by a simple solution method. Their nanostructures were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray absorption spectroscopy (XAS) and gas absorption techniques. The magnetic properties of the nanoparticles were studied by using a vibrating sample magnetometer (VSM). The increasing of Ni content with decreasing of crystallize size can improve magnetization. Moreover, the samples were fabricated as electrodes to study the electrochemical properties by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The high specific capacitances of the electrodes are in the range of 193–514 F g−1. Although the increasing of the Ni content leads to decreasing of the specific capacitances, the 5% Ni-doped BiFeO3 can improve the capacity retention (82%) after 500 cycles at 10 A g−1.

Electronic structure of nickel porphyrin NiP: Study by X-ray photoelectron and absorption spectroscopy

Energy distributions and properties of the occupied and empty electronic states for a planar complex of nickel porphyrin NiP are studied by X-ray photoemission and absorption spectroscopy techniques. As a result of the analysis of the experimental spectra of valence photoemission, the nature and energy positions of the highest occupied electronic states were determined: the highest occupied state is formed mostly by atomic states of the porphine ligand; the following two states are associated with 3d states of the nickel atom. It was found that the lowest empty state is specific and is described by the σ-type b1g MO formed by empty \(Ni3{d_{{x^2} - {y^2}}}\)-states and occupied 2p-states of lone electron pairs of nitrogen atoms. This specific nature of the lowest empty state is a consequence of the donor–acceptor chemical bond in NiP.

Reduction Behavior of Ni in a Ni/YSZ Anode Revealed by Operando Fluorescence X-ray Absorption Spectroscopy

Reduction behavior of Ni at a Ni/yttria-stabilized zirconia (YSZ) anode for a solid oxide fuel cell has been investigated by using operando fluorescence X-ray absorption spectroscopic technique. Characteristic four potential regions and two reduction rates of Ni were observed during thermochemical reduction of NiO to Ni by H2 gas at 1073 K. These characteristic regions and rates might be attributed to formation of NiO/Ni interface at the Ni/YSZ surface (in the vicinity of the gas inlet), that in the inside of the Ni/YSZ anode, and existence of H2O/H2 redox couple on the reduced Ni surface.

Phase formation investigation in PZT materials by Synchrotron X-ray absorption spectroscopy techniques

ABSTRACTPbZr1-xTixO3 (PZT) powders (x = 0.45–0.54) were synthesized by conventional solid state reaction method. The phase information was investigated by a combination of X-ray diffraction and X-ray absorption spectroscopy (XAS) techniques. The XRD measurements indicated the global phase formation of the prepared powders was the mixture of rhombohedral and tetragonal phases. However, the local phase formation around titanium atom was revealed using X-ray Absorption Near-Edge Structure (XANES), indicating the existence of monoclinic phase within the compositional range studied.

Effect of electric field on local structure of PZT single crystal studied by X-ray absorption spectroscopy technique

ABSTRACTThe aim of this work is to investigate the local structure of PbZr1−xTixO3 (PZT) single crystal with x = 0.44 under the application of electric field employing Synchrotron X-ray Absorption Near-Edge Structure (XANES) technique. In this experiment, PZT single crystal was subjected to 0.35 kV/mm and 0.70 kV/mm electric fields. The Ti K-edge XANES spectra reflect the significant change of the local structure of PZT unit cell before and after static electrical loading. From the XANES results, it was clearly seen that XANES spectral intensity gradually changed when the electrical load was applied. This can be caused by the shift of Ti atoms in the unit cell. The clear agreement between the measured and simulated XANES spectra was the supporting evidence of Ti off-center displacement in the PZT unit cell.

Application of x-ray absorption spectroscopy on local structure study in Fe-doped BaTiO3 ceramics

ABSTRACTIn this work, Fe-doped BaTiO3 ceramics were prepared by a conventional solid state reaction method. The effects of sintering temperature on the global and local structures of Fe-doped BaTiO3 ceramic (with 10 mole% Fe) were investigated by X-ray diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) techniques, respectively. The XRD measurements indicated the global structure of the prepared ceramic changed from pure tetragonal to hexagonal structure with increasing sintering temperature. From Synchrotron X-ray Absorption Near-Edge Structure (XANES) measurements, the oxidation state of Fe ions in BaTiO3 structure was clearly identified, as +3. The clear agreement between the experimental and theoretical XANES spectra indicated Fe substituting on Ti site in BaTiO3 structure.

Temperature dependent local structure in BaTiO3 single crystal

ABSTRACTThe temperature dependent local structure of BaTiO3 single crystal was investigated by Synchrotron X-ray Absorption Spectroscopy (XAS) technique. From the X-ray Absorption Near-Edge Structure (XANES) measurements at Ti K-edge, it was seen that the local structure around Ti atom gradually changed with increasing temperature, showing the phase transition from tetragonal to cubic. A comparison between the measured and calculated XANES spectra revealed the gradual change of local structure as a result of the decreasing c/a ratio.

Integration of Active Nickel Oxide Clusters by Amino Acids for Water Oxidation

The move toward sustainable hydrogen production from water using renewable energy, a highly efficient oxygen evolution electrocatalyst, is crucial because water-splitting efficiency is restricted to the oxygen evolution capability, which is insufficient compared to the hydrogen evolution reaction. Herein, we report a new method that improves the oxygen evolution activity by integration of active nickel oxide clusters using amino acids, meaning that the amount of electrodeposited nickel oxides is increasing with maintaining the catalytic activity. This method enhances the catalytic activity because the reaction sites drastically increase in three dimensions. The detailed reaction mechanism was investigated using operando UV/vis absorption and Ni K-edge X-ray absorption spectroscopic techniques, which suggested that amino acids such as glycine, alanine, and glutamine promoted the electrodeposition of NiO6 octahedral structure clusters. Meanwhile, the analysis of N and O K-edge X-ray absorption spectra showe...

Effective and Selective Trapping of Volatile Organic Sulfur Derivatives by Montmorillonite Intercalated with a μ-oxo Fe(III)-Phenanthroline Complex.

The μ-oxo Fe(III)-phenanthroline complex [(OH2)3(Phen)FeOFe(Phen) (OH2)3]+4 intercalated in montmorillonite provides a stable hybrid material. In this study, the ability and efficiency of this material to immobilize thiols in gas phase, acting as a trap at the solid-gas interface, were investigated. Aliphatic thiols containing both hydrophilic and hydrophobic end groups were chosen to test the selectivity of this gas trap. DR-UV-vis, IR, elemental analysis, thermal analysis and evolved gas mass spectrometry, X-ray powder diffraction, and X-ray absorption spectroscopy techniques were employed to characterize the hybrid material before and after thiol exposure and to provide information on the entrapping process. Thiol immobilization is very large, up to 21% w/w for heptanethiol. In addition, evidence was obtained that immobilization occurs through the formation of a covalent bond between the iron of the complex and the sulfur of the thiol. This provides an immobilization process characterized by a higher stability with respect to the methods based on physi-adsorption. Thiol immobilization resulted thermally reversible at least for 20 adsorption/desorption cycles. Unlike standard desulfurization processes like hydrotreating and catalytic oxidation which work at high temperatures and pressures, the present system is able to efficiently trap thiols at room temperature and pressure, thus saving energy. Furthermore, we found that the selectivity of thiol immobilization can be tuned acting on the amount of complex intercalated in montmorillonite. In particular, montmorillonite semisaturated with the complex captures both hydrophobic and hydrophilic thiols, while the saturated montmorillonite shows a strong selectivity toward the hydrophobic molecules.

Lead (II) complexation with 3-mercaptopropyl-groups in the surface layer of silica nanoparticles: Sorption, kinetics and EXAFS/XANES study

Abstract In this work, mono-dispersed mercapto-functionalized silica (SiO2@SH) particles with a narrow particle size distribution of around (420 ± 10) nm were prepared by the sol–gel method for the adsorption of aqueous dissolved lead (Pb2 +) ions from modeled wastewater. Transmission Electron Microscopy (TEM), in combination with Energy-Dispersive X-ray Spectroscopy (EDXS), was used to obtain information about the particle size and morphology of the prepared samples. Dispersive X-ray Spectroscopy (EDXS) indicated strong signals of Si and S, implying successful completion after the mercapto ( SH) functionalization of the silica (SiO2) surfaces. Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the occurrences of Si–O–Si and SH vibrations within the samples and, thus, come to a conclusion about the formations of the mercapto-functionalized samples. Analysis was performed of Pb2 + adsorption with mercapto-groups ( SH) on the surface of the SiO2@SH particles. The results for Pb2 + adsorptions from the modeled wastewater showed affinity of around 55% and the obtained value of the maximum amount of adsorbed Pb2 + ions with the SiO2@SH samples was 10.82 mg/g under the conditions used during this study. The results of the adsorptions were fitted with the Langmuir and Freundlich isotherm models and the pseudo-first and pseudo-second kinetic models were evaluated. We employed Pb-L3 edge X-ray absorption spectroscopy techniques XANES (X-ray Absorption Near Edge Structure) and EXAFS (Extended X-ray Absorption Fine Structure) for probing the local environments of Pb within the tentative Pb-S complex after adsorptions of Pb2 + by the mercapto groups. The EXAFS/XANES analysis indicated complete Pb2 + complexation with two SH groups of the prepared SiO2@SH samples.

In-situ high-energy-resolution X-ray absorption spectroscopy for UO2 oxidation at SSRF

Based on the high-energy-resolution fluorescence spectrometer on the BL14W1 beamline at Shanghai Synchrotron Radiation Facility, an in-situ high-energy-resolution X-ray absorption spectroscopy technique, with an in-situ heating cell, was developed. The high-energy-resolution fluorescence detection for X-ray absorption near-edge spectroscopy (HERFD-XANES) was tested in a UO2 oxidation experiment to measure the U L3-edge, with higher signal-to-noise ratio and higher-energy-resolution than conventional XANES. The technique has potential application for in-situ study of uranium-based materials.

High-Performance Asymmetric Supercapacitors of MnCo2O4 Nanofibers and N-Doped Reduced Graphene Oxide Aerogel.

The working potential of symmetric supercapacitors is not so wide because one type of material used for the supercapacitor electrodes prefers either positive or negative charge to both charges. To address this problem, a novel asymmetrical supercapacitor (ASC) of battery-type MnCo2O4 nanofibers (NFs)//N-doped reduced graphene oxide aerogel (N-rGOAE) was fabricated in this work. The MnCo2O4 NFs at the positive electrode store the negative charges, i.e., solvated OH-, while the N-rGOAE at the negative electrode stores the positive charges, i.e., solvated K+. An as-fabricated aqueous-based MnCo2O4//N-rGOAE ASC device can provide a wide operating potential of 1.8 V and high energy density and power density at 54 W h kg-1 and 9851 W kg-1, respectively, with 85.2% capacity retention over 3000 cycles. To understand the charge storage reaction mechanism of the MnCo2O4, the synchrotron-based X-ray absorption spectroscopy (XAS) technique was also used to determine the oxidation states of Co and Mn at the MnCo2O4 electrode after being electrochemically tested. The oxidation number of Co is oxidized from +2.76 to +2.85 after charging and reduced back to +2.75 after discharging. On the other hand, the oxidation state of Mn is reduced from +3.62 to +3.44 after charging and oxidized to +3.58 after discharging. Understanding in the oxidation states of Co and Mn at the MnCo2O4 electrode here leads to the awareness of the uncertain charge storage mechanism of the spinel-type oxide materials. High-performance ASC here in this work may be practically used in high-power applications.

Towards Printed Organic Light‐Emitting Devices: A Solution‐Stable, Highly Soluble CuI–NHetPHOS

The development of iridium-free, yet efficient emitters with thermally activated delayed fluorescence (TADF) was an important step towards mass production of organic light-emitting diodes (OLEDs). Progress is currently impeded by the low solubility and low chemical stability of the materials. Herein, we present a CuI -based TADF emitter that is sufficiently chemically stable under ambient conditions and can be processed by printing techniques. The solubility is drastically enhanced (to 100 g L-1 ) in relevant printing solvents. The integrity of the complex is preserved in solution, as was demonstrated by X-ray absorption spectroscopy and other techniques. In addition, it was found that the optoelectronic properties are not affected even when partly processing under ambient conditions. As a highlight, we present a TADF-based OLED device that reached an efficiency of 11±2 % external quantum efficiency (EQE).

In situ X-ray absorption spectroscopy study on water formation reaction of palladium metal nanoparticle catalysts

Proper management of hydrogen gas is very important for safety security of nuclear power plants. Hydrogen removal by water formation reaction on a catalyst is one of the candidates for creating hydrogen free system. We observed in situ and time-resolved structure change of palladium metal nanoparticle catalyst during the water formation reaction by using X-ray absorption spectroscopy technique. A poisoning effect by carbon monoxide on catalytic activity was also studied. We have found that the creation of oxidized surface layer on palladium metal nanoparticles plays an important role for the water formation reaction process.

(Invited) In-Situ Spectroscopic Observation of Lithium Sulfur Batteries upon Cycling

Sulfur, with its a high theoretical specific capacity (1675 mAh/g), is an abundant, low cost, and environmentally friendly element that has been extensively studied as a promising electrode material for rechargeable lithium batteries. However, low sulfur utilization and a poor cycle life are among the issues limiting its commercialization. Several of these issues are related to the electronically insulating nature of elemental sulfur and the dissolution of the resulting lithium polysulfides (Li2Sn, 2 ≤ n ≤ 8) formed during the discharge process, especially in a battery comprising of liquid electrolytes. As a result, these polysulfide species readily diffuse to the anode side causing formation of a highly resistant layer on the lithium metal anode that leads to the reduction of Li+ ion mobility and rapid capacity fading during cycling. The interactions between the support and elemental sulfur/lithium polysulfides play an important role in sulfur utilization and cycling stability. To obtain a better understanding of the interactions, in situ Raman and X-ray absorption Spectroscopic techniques together with DFT computation were developed and employed in this work. The Raman peaks observed were assigned successfully by the conjunction with the computational and experimental approaches. The results based on the spectroscopic characterization of the different components reveal that the undesired shuttle mechanism causing the passivation of Li anode can be suppressed due to the preferential interaction between elemental sulfur/lithium polysulfides with the designed supports or polymer electrolytes. This work has opened a new path towards the development of new supports and polymer electrolytes for lithium sulfur battery applications.

Operando Observation and Analysis of Reaction Distribution in Composite Electrodes for All-Solid-State Lithium Ion Batteries

All-solid-state lithium ion secondary battery is a promising next generation one in terms of safety, energy density and flexibility in shape. In the all-solid-state lithium ion secondary battery, composite electrodes are organized by particles of active material, solid electrolyte, conductive additive material and binder forming three-dimensional ionic and electronic conduction pass. It is recognized the suitable ratio of active material is an important factor against high volumetric energy density and rate performance. Inhomogeneity of reaction in composite electrodes derived from their morphology affects the battery performance. Therefore, it is necessary to understand the relationship between morphology of composite electrode and reaction distribution phenomenon. Nevertheless, there are few studies from such a point of view both for the liquid and solid electrolyte system, 1-4 and it has never been reported observing the phenomenon experimentally in solid-state battery. In this study, we developed operando 2D-imaging X-ray Absorption Spectroscopic (2D-XAS) technique to investigate the reaction distribution within composite electrodes of in-plane and simulated cross sectional direction. We discuss here the correlation between electrochemical behavior and electrode morphology along two kinds of electrodes composed by different binder material. Composite electrodes were prepared by mixing active material (LiNi1/3Co1/3Mn1/3O2 (NCM)), solid electrolyte (75Li2S-25P2S5 glass (SE)), conductive additive (Acetylene Black (AB)) and binder with some solvent in the ratio of NCM:SE:AB:binder = 70:30:3:3 [wt%]. Styrene butadiene copolymer rubber (SBR) or styrene ethylene butylene styrene copolymer (SEBS) was used as a binder material in each electrochemical cell. The composite electrodes and SE sheets were pressed together under 300 MPa uniaxially, and then placed in laminate-type layered cells with counter electrodes (Li metal foil). All the process was done in Ar-filled grove-box. These cells were designed to observe the reaction distribution in not only the in-plane but also the cross sectional direction by the operando 2D-XAS measurements. The operando 2D-XAS measurements were performed at BL37XU, SPring-8, Japan. Ni K-edge XAS spectra of the NCM electrodes were collected every 20 minutes using CMOS 2D detector with a spatial resolution of 1.3 square micrometer, under running 1/40 C rate charging program. Hereafter, we refer to the two kinds of electrochemical cells with SBR binder and with SEBS as SBR-cell and SEBS-cell, respectively. In the same electrochemical measurement condition, the SBR-cell showed higher capacity at 10th cycle than the SEBS-cell. Also, it was observed that the SEBS-cell had low density, and that active material and SE distributed not homogeneously over the whole electrode from a cross section image through Scanning Electron Microscope.During the 2D-XAS measurements, galvanostatic charge tests were performed for both of the SBR- and the SEBS-cell with the State Of Charge (SOC) range of 0-22% under stable voltage. The x-ray absorption image obtained from the 2D-XAS measurements, means the existence ratio of the active material in the composite electrode (containing information along thickness dimension), reflecting the dispersiveness of the active material. The active material in the SBR-cell dispersed homogeneously, while that in the SEBS-cell localized. This suggests that dispersiveness of the active material in the composite electrode was influenced by characteristics of the binder material. Concerning the reaction distribution behavior in in-plane, the SBR-cell almost homogeneously reacted across the electrode from the initial of the charging process. In contrast, some specific regions reacted preferentially in the SEBS-cell even at the early stage of the charging process, which generated the distribution clearly through the measurement. Comparing existence ratio of Ni with reaction mapping in the both composite electrodes, it suggests that the reaction occurs preferentially in specific region containing a lot of active material particles along thickness dimension when they are greatly localized. In terms of cross sectional study of the composite electrodes, we observed that the electrode reaction proceeded isotropically from near the electrolyte to the current collector side in the case of charging. This result indicates that the limiting factor here is the ionic conductivity.

Determining Factors for Charge-Discharge Performances of Composite Electrode in Lithium-Ion Battery

Composite electrodes containing active materials, carbon and binder are widely used in Li-ion batteries. It is well known that their morphology influences the electrochemical performance of batteries and we have tuned the parameters of composite electrodes such as porosity, compounding ratio and thickness.1 , 2 )However, the tuning of composite electrodes has been performed on an empirical basis because decision factors for the improved performance in tuning composite electrodes have not clearly understood. From a practical standpoint, it is important to scientifically develop the design guide for composite electrodes. There are a number of resistances in composite electrodes. Since the electrode reaction proceeds in regions with lower resistance, reaction distribution is happened within the composite electrode. It is required to understand the relationship among battery performance, reaction distribution and electronic/ionic conductivity in composite electrodes. Previously some researchers have reported the distribution model from the theoretical aspect.3 , 4 ) Recently there are reports made to directly observe the reaction distribution of composite electrodes.5-8 ) Unfortunately these advanced studies just observed distribution phenomena without addressing the decision factor for the distribution and electrode performance. This study aims to explain their relationship from the experimental results. To investigate the cross-sectional reaction distribution occurring in composite electrodes, X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) technique was applied. For the measurement of electronic / ionic conductivity in composite electrodes we have developed a method for simultaneous measurement of electronic and ionic conductivities in composite electrodes.9) First, we examined the reaction distribution of LiFePO4 and LiCoO2 electrodes. The reaction distribution in mono-phasic materials is relaxed by the potential gradient inside composite electrodes. On the other hand, the reaction distribution using LiFePO4 composite electrodes is remained under the open circuit condition.10) Because our XAS method detects the static information, we selected LiFePO4as the active materials. Composite electrodes using LiFePO4active material with low porosity cause a large polarization in high rate discharge reaction and decrease their capacity. In these electrodes, the discharge reaction occurs preferentially at the top surface of the electrode near electrolyte side. Further, low porosity results in a low effective ionic conductivity. This study clearly reveals the ionic conduction in the composite electrodes is the governing factor of lithium-ion battery performance. Control of ionic conductivities in composite electrodes is important to further improve the performance of lithium-ion batteries. The knowledge is useful to understand the decision factor for charge-discharge performance in Lithium-ion batteries and design principle of composite electrodes. REFERENCES: 1) W.Q. Lu, A. Jansen, D. Dees, G. Henriksen, J. Mater. Res., 25, 1656-1660 (2010). 2) C.C. Chang, L.J. Her, H.K. Su, S.H. Hsu, Y.T. Yen, J. Electrochem. Soc., 158, A481-A486 (2011). 3) M. Doyle, T.F. Fuller, J. Newman, J. Electrochem. Soc., 140, 1526-1533 (1993). 4) J. Newman, W. Tiedemann, J. Electrochem. Soc., 140, 1961-1968 (1993). 5) S.H. Ng, F. La Mantia, P. Novak, Angew Chem Int Edit, 48, 528-532 (2009). 6) J. Liu, M. Kunz, K. Chen, N. Tamura, T.J. Richardson, J. Phys. Chem. Lett., 1, 2120-2123 (2010). 7) K.C. Hess, W.K. Epting, S. Litster, Anal Chem, 83, 9492-9498 (2011). 8) J. Nanda, J. Remillard, A. O'Neill, D. Bernardi, T. Ro, K.E. Nietering, J.Y. Go, T.J. Miller, Adv Funct Mater, 21, 3282-3290 (2011). 9) Z. Siroma, J. Hagiwara, K. Yasuda, M. Inaba, A. Tasaka, J. Electroanal. Chem., 648, 92-97 (2010). 10) H. Tanida, H. Yamashige, Y. Orikasa, Y. Gogyo, H. Arai, Y. Uchimoto, Z. Ogumi, J. Phys. Chem. C, 120, 4739-4743 (2016).

On the Electronic Efffect of the Sn Atoms Towards Noble Metal Adsorption Sites: The Influence of the Structure on the Glycerol Electrooxidation Reaction

The searching for electrode materials with outstanding performance towards organic fuels electrooxidation reactions often is focused on polymetallic materials since they can exhibit a synergetic action resulting from electronic, geometric and/or bifunctional effects. However, as those effects are correlated, it is a difficult task to ascribe the improvement of the performance to a specific property and so to acquire a better understanding of the electrocatalytic process. It well known that Sn atoms exert a beneficial effect towards noble metal adsorption site that, on its turn, enhanced the kinetic of several organic fuels electrooxidation reactions. The enhancement is often suggested because of the electronic donor action of Sn atom; oxophilic action that provides the removal of intermediate species from the surface sites or a combination of these and other effects. The present work aims to elucidate the influence of the Sn atom present in the matrix of ordered intermetallic and alloy PtSn and PdSn (1:1 atomic ratio) nanoparticle materials towards the glycerol electrooxidation reaction in alkaline medium. Ordered intermetallic PtSn/C and PdSn/C nanoparticles were synthesized via modified polyol method and the same materials as alloys were synthesized via microemulsion route. All materials were obtained with similar particles diameters (~2nm) that assures the comparison of the electrode materials performances excluding the influence of the particle sizes. The materials were fully characterized by means of X-Ray Diffraction (XRD); Energy Dispersive Spectroscopy (EDS); High Resolution Transmission Electron Microscopy (HRTEM) and X-Ray Absorption Spectroscopy (XAS) techniques. Moreover, the electrochemical evaluation was performed by using cyclic voltammetry (CV) and chronoamperometry (CA) techniques and the identification of stable intermediates and products of the reactions were obtained from Mass Spectrometry (MS) technique. The electrochemical experiments were carried out in 0.5 mol.L-1 KOH electrolyte solution and all the potentials cited herein are referred to the Reversible Hydrogen Electrode (RHE). The obtained results have pointed to the best performance of the ordered intermetallic material PtSn/C. This best performance was attributed to the electronic donor effect of the Sn atom towards Pt adsorption site that optimized the adsorption of the glycerol molecule causing the dissociative adsorption of the fuel with the cleavage of the C-C bond. The electronic action of the Sn atom was confirmed by the XAS data. This phenomenon was reinforced by the identification of the following intermediates/products of the electrode reaction: formic acid (higher amount from the reaction taking place at ordered intermetallic PtSn/C); glyceric acid and glyceraldehyde (higher amount from the reaction taking place at alloy PtSn/C); glyceraldehyde/dihydroxyacetone (higher amount for ordered intermetallic PdSn/C) and tartronic acid (higher amount for alloy PdSn/C). The electrode reactions mechanisms were proposed for all systems pointing out to the possibility of using different materials for energy or high aggregate value chemicals production. FAPESP Proc. # 2013/05634-8 Figure 1