X-ray absorption spectroscopy studies

Tokunaga T., Pickering I.J., Brown G.E. Jr. X-ray absorption spectroscopy studies of selenium transformations in ponded sediments. Soil Sci Soc Am J 1996 60 781-790. 

Farquhar ML, Chamock JM, Livens FR, Vaughun DJ (2002) Mechanisms of arsenic uptake from aqueous solution by interaction with goethite, lepidocrocite, mackinawite and pyrite as X-ray absorption spectroscopy study. Environ Sci Tecnol 36 1757-1762... 

Rose, J., Moulin, I. et al. 2000. X-ray absorption spectroscopy study of immobilization processes for heavy metals in calcium silicate hydrates 1. Case of lead. Langmuir, 16, 9900-9906. 

The ligation of Ln3+ by DTPA, DTPA-BPA, DTPA-BGLUCA, and DTPA-BEN-GALAA has been derived from Nd3+-C distances as evaluated from Nd3+-induced 13C relaxation rate enhancements [5-8]. The distances obtained are in agreement with those observed in crystal structures of this class of compounds. H NMR studies on various paramagnetic [Ln(DTPA)]2 complexes [9,10] and 13C relaxation rate measurements on the diamagnetic [La(DTPA)] 2 confirm this mode of coordination [11]. A detailed X-ray absorption spectroscopy study of [Gd(DTPA)2-] also showed that the local structure around the Gd3+ ion in aqueous solution is similar to that in crystals [12]. 

Hattori, K., Takahashi, Y., Guillot, S. and Johanson, B. (2005) Occurrence of arsenic (V) in forearc mantle serpentinites based on X-ray absorption spectroscopy study. Geochimica et Cosmochimica Acta, 69(23), 5585-96. 

Grunwaldt J-D, Baiker A. Axial variation of the oxidation state of Pt-Rh/Al203 during partial methane oxidation in a fixed-bed reactor an in situ X-ray absorption spectroscopy study. Catal Lett. 2005 99 5. 

Ressler T, Hagelstein M, Hatje U, Metz W. In situ X-ray absorption spectroscopy studies on chemical oscillations in the C0/02 system on supported Pd catalysts. J Phys Chem B. 1997 101 6680. 

An X-Ray absorption spectroscopy study has been carried out on a carbon-supported Co and Co-Mo sulfide catalyst, the latter consisting of a fully sulfided Co-Mo-S (type II) phase. Detailed information on the structure of the cobalt sulfide phase is obtained by comparing the EXAFS and XANES spectra of the catalysts with those of CogS8 and CoS2 reference compounds. It is shown that the cobalt atoms in the Co-Mo-S phase have an octahedral-like sulfur coordination while the cobalt atoms in the sulfided Co/C catalyst have a larger fraction of octahedral cobalt than Co Sg. On the basis of these results, the high HDS activity of a sulfided Co/C catalyst can be understood since it appears that the structure of the cobalt sulfide phase in Co/C is in agreement with that in Co-Mo/C. In the Co-Mo-S phase, approximately one cobalt atom is in contact with one molybdenum atom at a distance of 2.85 A. 

Automobile exhaust catalysts typically contain noble metals such as Pt, Pd and Rh with a ceria promoter supported on alumina. Traditionally, the principal function of the Rh is to control emissions of nitrogen oxides (NO ) by reaction with carbon monoxide, although the increasing use of Pd has been proposed. For example, recent X-ray absorption spectroscopy studies of Holies and Davis show that the average oxidation state of Pd was affected by gaseous environment with an average oxidation slate between 0 and +2 for a stoichiometric mixture of NO and CO. Exposure of Pd particles to NO resulted in the formation of chemisorbed oxygen and/or a surface oxide layer. 

While more information pertaining to the electronic and atomic structures of the bare and silica-anchored bimetallic clusters is required - and DFT calculations and X-ray absorption spectroscopy studies are underway - it is striking that the performance of the small bimetallic clusters exceeds that of the pure Pd, the preferred catalyst in the industrial process [55]. Moreover, it is especially noteworthy that monometallic cluster catalysts exhibit such poor selectivity and activity, and that the presence of Sn as a stoichiometric component of the bimetallic clusters confers such a powerful influence on the minority (PGM) component. 

Van der Klink and Tong cover NMR studies of heterogeneous and electrochemical catalysts, and X-ray absorption spectroscopy studies are the focus of the chapter by Mukerjee. In Chapter 15, Stimming and Collins discuss STM and infrared spectroscopy in studies of fuel cell model catalyst. 

VK Yachandra, RD Guiles, AE McDermott, J Cole, RD Britt, SL Dexheimer, K Sauer and MP Klein (1987) Comparison ofthe structure ofthe manganese complex in the S, and S2 states of the photosynthetic oxygen-evolving complex An X-ray absorption spectroscopy study. Biochemistry 26 5974-5981... 

Moyes LN, Jones MJ, Reed WA, Livens FR, Chamock JM, Mosselmans JFW, Hennig C, Vaughan DJ, Patrick RAD (2002) An X-ray absorption spectroscopy study of neptunium(V) reactions with mackinawite (FeS). Environ Sci Technol 36 179-183... 

Moyes LN, Parkman RH, Chamock JM, Vaughan DJ, Livens FR, Hughes CR, Braithwaite A (2000) Uranium uptake from aqueous solution by interaction with goethite, lepidocrocite, muscovite, and mackinawaite An X-ray absorption spectroscopy study. Environ Sci Technol 34 1062-1068 Muller F, Besson G, Manceau A, Drits V-A (1997) Distribution of isomorphous cations within octahedral sheets in montmorillonite from Camp-Bertaux. Phys Chem Minerals 24 159-166 Muller J-P, Manceau A, Calas G, Allard T, Ildefonse P, Hazemann, J-L (1995) Crystal chemistry of kaolinite and Fe-Mn oxides relation with formation conditions of low temperature systems. Am J Sci 295 1115-1155... 

Towle SN, Bargar JR, Brown GE Jr, Parks GA (1999b) Sorption of Co(II) on metal oxide surfaces II. Identification of Co(II)(aq) adsorption sites on (1-102) and (0001) surfaces of a-Al203 by grazing-incidence XAFS spectroscopy. J Colloid Interface Sci 217 312-321 Trainor TP (2001) X-ray Scattering and X-ray Absorption Spectroscopy Studies of the Structure and Reactivity of Aluminum Oxide Surfaces. Ph.D. Dissertation. Department of Geological Environmental Sciences, Stanford University, Stanford, CA, USA Trainor TP, Brown GE Jr, Parks GA (2000) Adsorption and precipitation of aqueous Zn(II) on alumina powders. J Colloid. Interface Sci 231 359-372... 

Morton JD, Semrau JD, Hayes KF (2001) An X-ray absorption spectroscopy study of the structure and reversibility of copper adsorbed to montmorillonite clay. Geochim Cosmocliim Acta 65 2709-2722 Muller B, Sigg L (1992) Adsorption of lead(II) on the goethite surface Voltammetric evaluation of surface complexation parameters. J Coll Interf Sci 148 517-532 Neder RB, Burghammer M, Grasl T, Schulz H, Bram A, Fiedler S (1999) Refinement of the kaolinite structure from single-crystal synchrotron data. Clays Clay Miner 47 487-494 Needleman HL (1983) Low level lead exposure and neuropsychological performance In Lead versus health - Sources and effects of low level lead exposure. Rutter M, Russell JR (eds) Wiley, Chichester, p 229-248... 

X-ray absorption spectroscopy studies of metal carbonyl clusters... 

Existing data on phytochelatins and related polypeptides show that they differ from MT not only in biosynthesis but also in structure. Whereas no 3D structure has yet been reported, electronic spectroscopy (c.d. and UV-Vis) and EXAFS data on Cd-7-EC peptides led to different proposals as to the nature of the cadmium binding in such peptides, polynuclear cadmium thiolate aggregates versus isolated Cd(SCys)4 units, respectively. However, contrary to the conclusion of the previous work, a recent X-ray absorption spectroscopy study on Cd-7-EC peptides and model systems provides evidence for the formation of a polynuclear cadmium cluster. " ... 

Muller KJ, Hertz HG (1996) A ptirameter as an indicator for water-water association in solutions of strong electrolytes. J Phys Chem 100 1256-1265 Naslund L-A, Edwards DC, Wemet P, Bergmatm U, Ogasawara H, Pettersson LGM, Myneni S, Nilsson A (2005) X-ray absorption spectroscopy study of the hydrogen bond network in the bulk water of aqueous solutions. J Phys Chem A 109 5995-6002 Nickolov ZS, Miner JD (2005) J CoU Interf Sd 287 572-580... 

Chang, J. K., M. T. Lee, W. T. Tsai, M. J. Deng, and I. W. Sun. 2009. X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy studies on reversible insertion/desertion of dicyanamide anions into/from manganese oxide in ionic liquid. Chemistry of Materials 21 2688-2695. 

Corrias A, Casula MF, Ennas G, Marras S, Navarra G, Mountjoy G (2003) X-ray absorption spectroscopy study of FeCo-Si02 nanocomposites prepared by the sol-gel method. J Phys Chem B 107 3030-3039... 

Nalslund L-A, Edwards DC, Wemet Pet al (2005) X-ray absorption spectroscopy study of the hydrogen bond network in the bulk water or aqueous solutions. J Phys Chem A109 5995-6002... 

Sasaki K, Zhang J, Wang J, Uribe F, Adzic R, Sasaki K, Zhang J, Wang J, Uribe F, Adzic RR (2006) Platinum submonolayer-monolayer electrocatalysts an electrochemical and X-ray absorption spectroscopy study. Res Chem Intermediate 32 543-559... 

Deb A, Bergmann U, Cairns EJ, Cramer SP (2004) X-ray absorption spectroscopy study of the LixFeP04 cathode during cycling using a novel electrochemical in situ reaction cell. J Synchrotron Radial 11 497-504. doi 10.1107/S0909049504024641... 

Ziegelbauer JM, Gatewood D, Gulla AF, Ramaker DE, Mukerjee S (2006) X-ray absorption spectroscopy studies of water activation on RhxSy electrocatalyst for oxygen reduction reaction application. Electrochem Solid State Lett 9 A430-A434... 

The second mechanism is the electronic (or ligand) effect. It says that the additional element can modify the Pt surface electronically [50]. Chemisorption of CO on Pt involves the donation of an electron pair from the o anti-bonding orbital of CO to the unfilled 5rf-orbitals of Pt. A back donation of electrons from the Pt metal to the CO-orbitals further stabilizes their interaction. X-ray absorption spectroscopy studies [51 ] showed that alloying Sn with Pt caused partial filling of the Pt 5c -bands, resulting in a weaker chemisorption of CO. Combined with the easier adsorption of OH species on the Sn sites at low electrochemical potentials, the Pt-Sn alloy would enhance CO electrooxidation, and thus promote the... 

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