Activating 2D MoS2 by loading 2D Cu-S nanoplatelets for improved visible light photocatalytic hydrogen evolution, drug degradation, and CO2 reduction


Hierarchical Nickel Carbonate Hydroxide Nanostructures for Photocatalytic Hydrogen Evolution from Water Splitting


Estimation method of whiteline intensity of platinum compounds at L3 edge XANES and the oxidation number using a laboratory-type spectrometer

白金化合物L3吸収端XANESホワイトライン強度評価法と酸化数―実験室型装置による観察―


Direct ethyl acetate synthesis from ethanol over amorphous-, monoclinic-, tetragonal ZrO2 supported copper catalysts prepared from the same zirconium source


Analysis of Leachate Copper from Sediment at a Small Abandoned Mine Site by Handy-type Liquid Electrode Plasma Atomic Emission Spectrometer

Sediment, soil and drainage water were collected at an abandoned copper mine, and the leachate copper prepared with 1M HCl were qualitatively analyzed by a handy elemental analyzer based on liquid electrode plasma atomic emission spectrometry (LEP-AES). Quantitative values obtained by the handy analyzer with standard addition or conventional calibration method combining with self-internal standard method, and ones by flame atomic absorption spectrometer were compared. The analytical condition for LEP-AES, the accuracy and the precision were discussed. The elongation of interval of pulsed applied voltage enhanced intensities of emission line, but background rising for copper emission line overlapping tail of broad OH band prevent expected improvement of the limit of detection. Copper species in sediment exist as divalent basic copper sulfate confirmed by XANES/EXAFS spectra recorded by a laboratory type spectrometer.


Hydrothermally Synthesized Poorly Crystalline Binary Oxides with ZrW2O8 composition: Preparation, Structural Analysis, and Catalytic Activity for the Alkylation of Anisole with Benzyl Alcohol


Ethanol conversion over Ga2O3-ZrO2 solid solution: empirical evidence of the reaction pathway, the surface acid-base properties, and the role of gallium ions


Visualization Analysis of Pt and Co Species in Degraded Pt3Co/C Electrocatalyst Layers of a Polymer Electrolyte Fuel Cell Using a Same-View Nano-XAFS/STEM-EDS Combination Technique


Ga ion-doped ZrO2 Catalyst Characterized by XRD, XAFS, and 2-Butanol Decomposition

Group 2, 3, and 13 element-doped zirconium oxide catalysts M-ZrO (M = Mg, Sr, Y, La, Ce, Sm, Er, Yb, B, Al, Ga, In, and Tl; 5 mol%) were prepared by impregnation of each metal salt aqueous solution on amorphous zirconium hydroxide, followed by calcination at 773 K. The M-ZrO samples were characterized by the catalytic performance of 2-butanol decomposition at 573 K, XRD, XANES and EXAFS spectroscopic techniques. Detailed analyses were performed herein for a series of Ga-ZrO with various doping amounts in the range of 1 - 60 mol%. The addition of Group 2 and 3 elements little influenced the catalytic performance of ZrO itself to promote dehydration to produce 1-butene with 90% selectivity. Ga-ZrO and In-ZrO gave methyl ethyl ketone as the main product via dehydrogenation. The doped Ga ion mainly existed inside the bulk of zirconia by forming the GaZrO solid solution up to 5 mol%. Highly doped species more than 10 mol% aggregated to form ϵ-GaO. Each fraction forming the solid solution and GaO-like species was evaluated by XANES analysis.


Evaluation of the Electronic and Local Structure of Mn in Proton-Conducting Oxide, Ca(Zr,Mn)O3-δ, to Elucidate a Direct Hydrogen-Dissolution Reaction


形状の異なる焦電結晶積層体によるX線発生挙動および放電特性

形状の異なる焦電結晶積層体によるX線発生挙動および放電特性

Advances in X-Ray Chemical Analysis, Japan


Observation of Degradation of Pt and Carbon Support in Polymer Electrolyte Fuel Cell Using Combined Nano-X-ray Absorption Fine Structure and Transmission Electron Microscopy Techniques

It is hard to directly visualize spectroscopic and atomic-nanoscopic information on the degraded Pt/C cathode layer inside polymer electrolyte fuel cell (PEFC). However, it is mandatory to understand the preferential area, sequence, and relationship of the degradations of Pt nanoparticles and carbon support in the Pt/C cathode layer by directly observing the Pt/C cathode catalyst for the development of next-generation PEFC cathode catalysts. Here, the spectroscopic, chemical, and morphological visualization of the degradation of Pt/C cathode electrocatalysts in PEFC was performed successfully by a same-view combination technique of nano-X-ray absorption fine structure (XAFS) and transmission electron microscopy (TEM)/scanning TEM-energy-dispersive spectrometry (EDS) under a humid N atmosphere. The same-view nano-XAFS and TEM/STEM-EDS imaging of the Pt/C cathode of PEFC after triangular-wave 1.0-1.5 V (startup/shutdown) accelerated durability test (tri-ADT) cycles elucidated the site-selective area, sequence, and relationship of the degradations of Pt nanoparticles and carbon support in the Pt/C cathode layer. The 10 tri-ADT cycles caused a carbon corrosion to reduce the carbon size preferentially in the boundary regions of the cathode layer with both electrolyte and holes/cracks, accompanied with detachment of Pt nanoparticles from the degraded carbon. After the decrease in the carbon size to less than 8 nm by the 20 tri-ADT cycles, Pt nanoparticles around the extremely corroded carbon areas were found to transform and dissolve into oxidized Pt-O species.


Relation between intensity of XANES pre-edge and XES Kb5 of vanadium and manganese compounds


実験室型X線吸収分光装置を用いた遠隔山岳地域で採取された湿性沈着中の長距離輸送エアロゾル中に含まれる鉄の化学状態分析


Sulfur Chemical State and Chemical Composition of Insoluble Substance in Soft Rime, Hard Rime and Snow collected on Remote and Rural Areas in Japan using WDXRF


Discrepancy in the quantitative oxidation-state analysis of Eu species in sulfide phosphors by K-, L1-, and L3-edge XANES spectrometry: Choice of absorption edge and measurement mode

Journal of Analytical Atomic Spectrometry


Role of iron modifier on boron atomization process using graphite furnace-atomic absorption spectrometry based on speciation of iron using X-ray absorption fine structure

Spectrochimica Acta. Part B: Atomic Spectroscopy


High temperature degradation mechanism of a red phosphor, CaAlSiN3:Eu for solid-state lighting


Atomization Mechanism of Boron by Graphite Furnace Atomic Absorption Spectrometry using Iron Matrix Modifier

鉄マトリクス修飾剤を用いた黒鉛炉原子吸光法によるホウ素の原子化機構


Structural transformation of tungsten-zirconium hydroxide crystals upon calcination characterized by XRD, XAFS and acid catalyzed reaction

タングステンジルコニウムオキシ水酸化物結晶脱水過程のXRD/XAFS観察およびその酸触媒特性

W:Zr 比が2:1 の二元系水酸化物を水熱合成法にて調製し，水熱処理の保持時間および焼成温度の異なる物質の構造をX 線回折，X 線吸収分光法で検討し，酸触媒特性を評価した．453 K での水熱処理では12 時間までは高表面積かつ結晶性の低い化学種(I 相)が生じ，24 時間以降で結晶性の高い水和物(ZWOH 結晶)が得られた．ZWOH 結晶は573-773K で結晶性の低いZrW2O8 多形(II 相)，823-873K で立方晶ZrW2O8 へ変化することをX 線分析，UV-Vis 分光法および熱重量分析で確認した．I 相はアニソールのベンジルアルコールによるアルキル化を促進する固体強酸触媒として機能し，873K 焼成体が最高活性を示した．ZWOH 結晶およびZrW2O8 はアルキル化活性を示さなかった．立方晶系ZrW2O8 の結晶性の低いI 相が混在しても通常のXRD 解析では検出困難であるが，表面積測定および活性試験を併用すると混在の推定が可能であった．Tungsten zirconium hydroxides (ZWOH) with the molar ratio of W/Zr =2 were synthesized by a hydrothermal process at 453 K for 6-72 h. Structure of the hydroxides with different crystallinity and the transformation upon calcination were characterized by XRD, XAFS, UV-vis spectroscopic techniques. The ill-crystallized ZWOH with large surface area (>100m2 ·g-1; phase-I) was formed via hydrothermal treatment till 12 h, and well crystallized ZrW2O7(OH)2(H2O)2 (< 2 m2 ·g-1; c-ZWOH) was formed after 24 h. W L-edge XAFS, optical bandgap and thermal gravity analyses gave direct evidence to support the previous suggestion about dehydration process of c-ZWOH to ZrW2O8, where ZrW2O8 polymorphism with low crystallinity (phase-II) and cubic ZrW2O8 crystal formed after calcination in the range of 573-773 and 823-873 K, respectively. The ZWOH phase-I was found to promote alkylation of benzylalcohol with anisole, and the activity exhibited the maximum after calcination at 873 K. The c-ZWOH and ZrW2O8 polymorphisms were catalytically inert for the reaction. Existence of active phase-I as a minor species in ZrW2O8 little influence on XRD pattern, but surface area measurements and the catalytic performance might help to evaluate fraction of phase-I in the Zr-W-O system. The ZWOH phase-I was candidate for a model catalyst of tungstated zirconia strong solid acid to investigate the acidity generation mechanism.


Key Structural Kinetics for Carbon Effects on the Performance and Durability of Pt/Carbon Cathode Catalysts in Polymer Electrolyte Fuel Cells Characterized by in Situ Time-Resolved XAFS


Spatially Non-Uniform Degradation of Pt/C Cathode Catalysts in Polymer Electrolyte Fuel Cells Imaged by Combination of Nano XAFS and STEM-EDS Techniques


Generation of Strong Acid Sites on Yttrium-Doped Tetragonal ZrO2-Supported Tungsten Oxides: Effects of Dopant Amounts on Acidity, Crystalline Phase, Kinds of Tungsten Species, and Their Dispersion


Analysis of hexavalent chromium species in household articles by a laboratory-type X-ray absorption spectrometer

実験室系XAFS装置を用いた皮革，めっき，鉱石中の六価クロムの分析

身の回りにあるクロムを含む多様な物品のクロムK 殻X 線吸収スペクトルを実験室系装置により測定し，XANES スペクトル解析により三価クロム種に対する六価種の定量分析を行った．高感度および高分解モードのスリット設定で測定されたXANES スペクトルの形状比較より，定量分析のために適した測定条件について論じた．全クロム中六価クロム種の定量はプリエッジピーク高さを用い，二種類の六価クロム化合物を用いても検量線の傾きの差は 1% であった．解析の結果，測定した三点の革製品およびクロム白雲母には六価クロム種は含まれていなかった．虹色光沢を呈したクロメート試料からは六価クロム種が検出された．Cr K-edge XANES spectra of various kinds of household articles such as leather products and chromate conversion coatings were recorded with a laboratory-type X-ray absorption spectrometer for quantitative analysis of hexavalent chromium species. The low energy resolution settings were found to be enough and suitable for the quantitative analyses with the spectrometer. The tiny but distinct preedge peak characteristics to hexavalent chromium species could be detected in XANES spectra of chromate conversion coatings with iridescent color, and the ratios of hexavalent to sum of hexa- and trivalent chromium species (Cr6 + /(Cr6 + + Cr3 + )) were calculated by the preedge peak height.

Advances in X-Ray Chemical Analysis, Japan


Analysis of d-electron state of platinum salts on silica during thermal decomposition by a laboratory-type X-ray absorption spectrometer Choice of parameters for in-situ experiments

実験室系XAFS装置によるシリカ担持白金触媒前駆体のその場測定条件の検討および熱分解過程での白金5d軌道空孔密度分析

The decomposition behavior of H2PtCl6 or Pt(NH3)4Cl2 supported on amorphous silica was investigated by X-ray absorption near edge spectroscopy using a laboratory-type spectrometer. The choice of a monochromator crystal, the slit width and the acquisition time for in situ measurements of catalyst samples is discussed. The whiteline intensities at the Pt L3 edge XANES did not always reflect on the oxidation state of the platinum species, but on the d-orbital occupancy, as pointed out previously. The changing behavior of the Pt d-orbital occupancy of platinum species on silica upon a thermal treatment in air was evaluated by Pt L2,3 edge XANES with Mansour's method. Metallic platinum formed on silica after calcination at 773 K under air, but cationic platinum species were suggested to have remained.


Surface-regulated Nano-SnO2/Pt3Co/C Cathode Catalysts for Polymer Electrolyte Fuel Cells Fabricated by A Selective Electrochemical Sn Deposition Method

We have achieved significant improvements for the oxygen reduction reaction activity and durability with new SnO2-nanoislands/Pt3Co/C catalysts in 0.1 M HClO4, which were regulated by a strategic fabrication using a new selective electrochemical Sn deposition method. The nano-SnO2/Pt3Co/C catalysts with Pt/Sn = 4/1, 9/1, 11/1, and 15/1 were characterized by STEM-EDS, XRD, XRF, XPS, in situ XAFS, and electrochemical measurements to have a Pt3Co core/Pt skeleton-skin structure decorated with SnO2 nanoislands at the compressive Pt surface with the defects and dislocations. The high performances of nano-SnO2/Pt3Co/C originate from efficient electronic modification of the Pt skin surface (site 1) by both the Co of the Pt3Co core and surface nano-SnO2 and more from the unique property of the periphery sites of the SnO2 nanoislands at the compressive Pt skeleton-skin surface (more active site 2), which were much more active than expected from the d-band center values. The white line peak intensity of the nano-SnO2/Pt3Co/C revealed no hysteresis in the potential up-down operations between 0.4 and 1.0 V versus RHE, unlike the cases of Pt/C and Pt3Co/C, resulting in the high ORR performance. Here we report development of a new class of cathode catalysts with two different active sites for next-generation polymer electrolyte fuel cells.

Journal of the American Chemical Society


Effect of Aging Method on Adsorption and Elution of Phosphate in Mg/Fe Layered Double Hydroxide


Same-View Nano-XAFS/STEM-EDS Imagings of Pt Chemical Species in Pt/C Cathode Catalyst Layers of a Polymer Electrolyte Fuel Cell

The Journal of Physical Chemistry Letters


Effect of Annealing on Crystal and Local Structures of Doped Zirconia Using Experimental and Computed Methods


Correlation between structure and mixed ionic-electronic conduction mechanism for (La1-xSrx)CoO3-d using synchrotron X-ray analysis and first principles calculations

Journal of Materials Chemistry. A, Materials for Energy and Sustainability


Pt Chemical Species Mapping in Polymer Electrolyte Fuel Cells by Spatially-Resolved Nano-XAFS Techniques

There is limited information on the mechanism for platinum oxidation and dissolution in Pt/C cathode catalyst layers of polymer electrolyte fuel cells (PEFCs) under the operating conditions though these issues should be uncovered for the development of next-generation PEFCs. Pt species in Pt/C cathode catalyst layers are mapped by a XAFS (X-ray absorption fine structure) method and by a quick-XAFS(QXAFS) method. Information on the site-preferential oxidation and leaching of Pt cathode nanoparticles around the cathode boundary and the micro-crack in degraded PEFCs is provided, which is relevant to the origin and mechanism of PEFC degradation.


In Situ Time-resolved XAFS of Transitional States of Pt/C Cathode Electrocatalyst in an MEA during PEFC Loading with Transient Voltages


Dependence of the oxygen reduction reaction activities of Pd-Co/C and Pd-Ni/C alloy electrocatalysts on the nanoparticle size and lattice constant


Temperature Dependence of X-Ray Emission Behavior from Stacked Pyroelectric Single Crystals

積層した焦電結晶によるX線発生挙動およびその温度依存性

積層させた薄片状タンタル酸リチウムまたはニオブ酸リチウム単結晶とセラミックヒーターを用いた小型高電場発生デバイスを製作し，これまでの検討より高温領域である室温から 650 K までの間でX 線発生実験を行った．473 K から650 K まで10–4 Pa 下で加熱すると最高28 keV のX 線が発生した．積層させた焦電結晶の側面では温度変化に伴い局所的な放電が繰り返し起こった．焦電結晶の形状と放電発生について議論した．

Advances in X-Ray Chemical Analysis, Japan


Performance and Durability of Pt/C Cathode Catalysts with Different Kinds of Carbons for Polymer Electrolyte Fuel Cells Characterized by Electrochemical and In-situ XAFS Techniques

The electrochemical activity and durability of Pt nanoparticles on different kinds of carbon supports in oxygen reduction reactions (ORR) were investigated using rotating disc electrodes (RDE) and the membrane electrode assemblies (MEA) of polymer electrolyte fuel cells (PEFC). The mass activity of Pt/C catalysts (ORR activity per 1 mg of Pt) at the RDE decreased, according to the type of carbon support, in the following order; Ketjenblack (KB) > acetylene black (AB) > graphene > multiwall carbon nanotube (MW-CNT) > carbon black (CB), whereas the average size of the Pt nanoparticles and the surface specific activity (ORR activity per electrochemical surface area) did not vary significantly between these carbon supports. These results indicate that the different mass activities of the Pt/C catalysts may originate from the differences in the fraction of Pt on the carbon supports which is available for utilization. The durability of the MEAs of the top two active catalysts Pt/KB and Pt/AB among the five catalysts was examined based on ORR performance, TEM and in situ XAFS. It was found that the performance of the Pt/KB cathode catalyst in PEFC MEA decreased significantly over 500 accelerated durability test (ADT) cycles, whereas the performance of the Pt/AB cathode catalyst in PEFC MEA did not decrease significantly during 500 ADT cycles, it was also found that the Pt/AB possesses 8 times higher durability compared with the Pt/KB. In situ Pt LIII-edge XAFS data in the ADT cycles and stepwise potential operations revealed the different oxidation-reduction behaviors of the Pt nanoparticles on the KB and AB supports. The Pt/KB was oxidized to form surface PtO layers more easily than the Pt/AB in the increasing potential operation from 0.4 VRHE to 1.4 VRHE, and the surface PtO layers of the Pt/AB were reduced to the metallic Pt state more readily than those of the Pt/KB in the decreasing potential operation from 1.4 VRHE to 0.4 VRHE. The XAFS analysis for the Pt valences and the coordination numbers of Pt-O and Pt-Pt demonstrated that the Pt/AB catalyst is more durable than the Pt/KB catalyst in PEFC MEAs.


Performances and Characterization of a Pt-Sn(oxidized)/C and Pt-Sn(reduced)/C Cathode Catalysts with a SnO2-decorated Pt3Sn Nanostructure for Oxygen Reduction Reaction in a Polymer Electrolyte Fuel Cell

We have prepared and characterized a SnO2-decorated Pt-Sn(oxidized)/C cathode catalyst in a polymer electrolyte fuel cell (PEFC). Oxygen reduction reaction (ORR) performance of Pt/C (TEC10E50E) remained almost unchanged or even tended to reduce in repeated I-V load cycles, whereas the I-V load performance of the Pt-Sn(oxidized)/C prepared by controlled oxidation of a Pt-Sn alloy/C sample with the Pt3Sn phase revealed a significant increase with increasing I-V load cycles. The unique increase in the ORR performance of the Pt-Sn(oxidized)/C catalyst was ascribed to a promoting effect of SnO2 nano-islands formed on the surface of Pt3Sn core nanoparticles. Also in a rotating disk electrode (RDE) setup, the mass activity of an oxidized Pt3Sn/C catalyst was initially much lower than that of a Pt/C catalyst, but it increased remarkably after 5000 rectangular durability cycles and became higher than that of the fresh Pt/C. The maximum power density per electrochemical surface area for the Pt-Sn(oxidized)/C catalyst in a PEFC was about 5 times higher than that for the Pt/C catalyst at 0.1-0.8 A cm(-2) of the current density. In situ X-ray absorption near-edge structure (XANES) analysis at the Pt LIII-edge in increasing/decreasing potential operations and at the Sn K-edge in the I-V load cycles revealed a remarkable suppression of Pt oxidation compared with the Pt/C catalyst at higher potentials and no change in the Sn oxidation state, respectively, resulting in higher performance and stability of the Pt-Sn(oxidized)/C catalyst due to the SnO2 nano-islands under the PEFC operation conditions. The SnO2 nano-island decorated Pt-Sn(oxidized)/C catalyst with a Pt3Sn alloy nanostructure is regarded as a promising candidate for a PEFC cathode catalyst.


Analysis of coordination environment of aluminum species in zeolites and amorphous silica-alumina by X-ray absorption and emission spectroscopy


Structural Kinetics on a Pt/C Cathode Catalyst with Practical Catalyst Loading in an MEA for PEFC Operating Conditions Studied by In Situ Time-Resolved XAFS

The structural kinetics of surface events on a Pt/C cathode catalyst in a membrane electrode assembly (MEA) with a practical catalyst loading (0.5 mgPt cm(-2)) for a polymer electrolyte fuel cell were investigated by in situ time-resolved X-ray absorption fine structure analysis (XAFS; time resolution: 100 ms) for the first time. The rate constants of structural changes in the Pt/C cathode catalyst in the MEA during voltage cycling were successfully estimated. For voltage-cycling processes, all reactions (electrochemical reactions and structural changes in the Pt catalyst) in the MEA were found to be much faster than those in an MEA with a thick cathode catalyst layer, but the in situ time-resolved XAFS analysis revealed that significant time lags similarly existed between the electrochemical reactions and the structural changes in the Pt cathode catalyst. The time-resolved XAFS also revealed differences in the structural kinetics of the Pt/C cathode catalyst for the voltage-cycling processes under N2 and air flows at the cathode.


Apparent Chemical Shifts at X-ray Absorption Edges of 3d-, 4f-, 5d- and 5p-elements for Empirical Chemical State Analysis

X線吸収スペクトルにおける見かけ上の化学シフトを利用した半経験的価数評価


X線回折法によるジルコニア結晶化過程に対する金属イオン添加効果の検討

X線回折法によるジルコニア結晶化過程に対する金属イオン添加効果の検討

ジルコニア担持酸化タングステン触媒の強酸性発現機構を解明するための予備検討として，水酸化ジルコニウムが873 -1073 K で焼成後に準安定正方晶を取り得る条件を探索するため，12 種類の金属イオンおよび硫酸イオンを添加した試料を調製し，結晶相の存在比率および格子面間隔をXRDにて検討した．種々のイオンを添加することでジルコニア結晶相の準安定正方晶を形成しうる温度領域が広がり，またその程度は添加金属種により異なった．水酸化ジルコニウムに金属イオンを添加した場合，準安定正方晶が存在しうる焼成温度範囲が狭い元素群のみ，773 K で焼成した際に観察される正方晶(101)面の格子面間隔が小さく，またそのイオン半径がジルコニウムイオンと近かった．


Pilot Study of Devises for Chemical Reactions with High Electric Field of Pyroelectric Crystal

焦電結晶を用いた密封系小型高電場発生ユニットの製作と電場触媒反応への応用に向けた試み

タンタル酸リチウム単結晶の温度変化に伴って形成する高電場を電場触媒反応に応用することを目標とし，反応基質を導入可能な密封系小型高電場発生ユニットを製作した．z軸長に対するz面の面積が異なる二種類の単結晶を用いてX線発生実験を行ったところ，単位z軸長あたりの生成した電場は薄片型結晶の方が大きかった．単結晶表面に白金箔を添加した状態でも，白金箔の特性X 線が最高エネルギー22 keV の白色X 線に重なって観測された．製作した密封空間のガス放出挙動を質量分析計で測定した．


Enhanced oxygen reduction reaction activity and characterization of Pt-Pd/C bimetallic fuel cell catalysts with Pt-enriched surfaces in acid media


Operando Time-Resolved X-ray Absorption Fine Structure Study for Surface Events on a Pt3Co/C Cathode Catalyst in a Polymer Electrolyte Fuel Cell during Voltage-Operating Processes


Evidence of two way X-ray emission from pyroelectric crystal

焦電結晶上での二元X線発生機構

タンタル酸リチウム単結晶の加熱/ 冷却に伴うX 線発生現象について，真空度および昇温温度を制御した実験を行い，その発生機構について検討した．X 線発生は既往の報告より三桁高い真空度10-4 Pa でも起こり，X線発生終了までの全積分強度は1 Paまで一定であった．タンタル酸リチウム単結晶の焦電性を利用したX線発生は，結晶表面近傍で起こる放電に伴って残留ガスより生じる高密度の荷電粒子の衝突を起源とする数分以内で終了する現象と，もともと残留ガス中に存在する荷電粒子を起源として10分以上継続するものとの二元機構であると結論された．焦電結晶の昇温する速度を一定にすることでX線発生強度が一定となる時間を延長することができた．


Selective uptake of phosphate ions on nanocomposite of Zr02 and layered double hydroxide


スチレン類二量化に有効な鉄シリカ触媒のXAFS法による構造解析

スチレン類二量化に有効な鉄シリカ触媒のXAFS法による構造解析

α-メチルスチレン二量化反応に活性を示す鉄ゾル-ゲル法にて調製した鉄シリカ触媒をX線回折およびX線吸収分光法により評価した．触媒中鉄種の存在状態は仕込みSi /Fe 比に依存し，100 以上では四面体FeOxCl4-x種，50以下ではα-Fe2O3 凝集種が主成分であり，その存在比をXANES解析により求めた．シリカマトリクスに捕捉された孤立FeOxCl4-x が活性種として機能し，固体酸性質を発現する機構について論じた．

Advances in X-Ray Chemical Analysis, Japan


Quantitative Chemical State Analysis of Supported Vanadium Oxide Catalysts by High Resolution Vanadium K-alpha Spectroscopy

Oxidation states of vanadium species on Al(2)O(3), SiO(2), and TiO(2) were quantitatively analyzed by least-squares fitting of V Kα spectra recorded with a two-crystal X-ray fluorescence spectrometer. Uncertainties of analytical results by the normalization procedure, and coefficient of validation and the reduction behavior of vanadium species by X-ray irradiation were discussed. The V(5+)/V(4+)/V(3+) ratios on Al(2)O(3), SiO(2), and TiO(2) calcined at 773 K in air were determined to be ca. 6/3/1, 3/6/1, and 5/4/1, respectively. The possible chemical states of vanadium species on supports were proposed.


Lead and Cadmium Concentrations in Winter Rain, Fresh Snow, Rime and Glaze Collected on the Top of Mt. Kajigamori, Kochi Prefecture in Shikoku Island, Japan

四国・高知県梶が森山頂の冬期降雨，降雪，樹氷および雨氷の鉛とカドミウム濃度

Winter rain, fresh snow, rime and glaze samples were collected on the top of Mt. Kajigamori (ALT. 1400 m), which is the watershed protection forest of Riv. Yoshinogawa with an altitude of 1400 m, Kochi, Shikoku Island in West Japan during the winter season of 2010 (December 2009 and March 2010). Lead and cadmium in the rain, snow, rime and glaze were analyzed by graphite furnace atomic absorption spectrometry together with the ionic components (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO2-, Br-, NO3-, PO43-, SO42-) by ion chromatography, and pH, E.C. during the winter season. In the back-trajectory over Russia-Japan Sea, very low concentrations of Pb and Cd were observed in all samples. From the back-trajectory over North China and Korea, it was considered that the observed relatively high concentration of Pb in snow and rime and Cd in rain showed a possibility of long-range transportation from the East Asis region. The low concentration of lead in rime ice and fresh snow collected at Mt. Tateeboshiyama (ALT. 1299 m) in Shobara city, Hiroshima (Mt. Hibasan quasi-national park) was observed with back-trajectry over Russia-Japan Sea.


四国山岳地帯土壌浸出水のハンディ液体電極プラズマ発光分析装置を用いる分析

四国山岳地帯土壌浸出水のハンディ液体電極プラズマ発光分析装置を用いる分析

The elemental analysis of a 1M hydrochloric acid leaching solution from soil samples in the mountain district of Shikoku was carried out by a portable liquid electrode plasma (LEP) atomic emission spectrometer. The contents of Na, K, Ca, Mg, Mn, and Fe were determined, and compared with those by flame photometry, flame atomic absorption spectrometry, ICP-MS and ICP-AES. The 600 V of the applied voltage was found to be suitable for the present sample solution at the use of a sample holder made of resin. The precision of the emission intensities for iterative measurements was improved by a normalization procedure with an emission line from the atomic hydrogen, and the relative standard deviations were ca. 20%. Results of quantitative analysis of soil-extracts by LEP atomic emission spectrometry were discussed based on geological data around the sampling area.

The elemental analysis of a 1M hydrochloric acid leaching solution from soil samples in the mountain district of Shikoku was carried out by a portable liquid electrode plasma (LEP) atomic emission spectrometer. The contents of Na, K, Ca, Mg, Mn, and Fe were determined, and compared with those by flame photometry, flame atomic absorption spectrometry, ICP-MS and ICPAES. The 600 V of the applied voltage was found to be suitable for the present sample solution at the use of a sample holder made of resin. The precision of the emission intensities for iterative measurements was improved by a normalization procedure with an emission line from the atomic hydrogen, and the relative standard deviations were ca. 20%. Results of quantitative analysis of soil-extracts by LEP atomic emission spectrometry were discussed based on geological data around the sampling area.


Formation of chlorinated aromatics in model fly ashes using various copper compounds

Various copper compounds found in fly ash are related to the formation of chlorinated aromatics. The formation potentials of chlorinated aromatics in different model fly ashes containing various copper compounds and the chemical behavior of such copper compounds were investigated. In model fly ash with copper metal, hydroxide, carbonate, or oxides, the generated amounts of chlorobenzene (CBz) and polychlorinated biphenyls (PCBs) and the average chlorination numbers were low and at the same level, respectively. The maximum generated amounts of chlorinated aromatics were observed at 300 degrees C. Although X-ray absorption near edge structure (XANES) spectra indicated that the chemical form of copper compounds changed little, they were found to promote the formation of chlorinated aromatics. Therefore, these copper compounds play the same role as CuO. On the other hand, in model fly ash with copper chloride, the generated amounts of CBz and PCBs were quite high and the average chlorination numbers was high. Dynamic changes were observed in XANES spectra, and the pre-edge peak attributed to monovalent copper compounds appeared at around 300 degrees C. A large difference was observed between these two groups in the amount of CuCl generated and the homologs of chlorinated aromatics present, indicating that CuCl played an important role in the formation of chlorinated aromatics.


Portable TXRF Spectrometer with 10-11g Detection Limit and Portable XRF Spectromicroscope with Sub-mm Spatial Resolution


蛍光X線スペクトルのケミカルシフトを用いた鉄鋼スラグ中Alの化学状態分析

蛍光X線スペクトルのケミカルシフトを用いた鉄鋼スラグ中Alの化学状態分析

鉄鋼スラグに含まれるアルミニウムの化学状態を分析することを目的とし，X 線分光法を用いて，Al Kα線のケミカルシフトと配位数との相関からスラグ中に含まれるアルミニウムの化学状態分析を行った．スラグ試料としては，アルニミウムを約14 ∼ 31[mass%] 含む高炉スラグ及び製鋼スラグを用いた．また，実際にスラグ試料を測定する前に，配位数の既知であるアルミニウム化合物について蛍光X線分光法により，配位数とケミカルシフトとの相関を確認した．これらの結果，本研究で用いたスラグ試料に含まれるアルミニウムはいずれも4 配位型(AlO4 型)の構造であることが結論された．


焦電結晶の小型高エネルギーX線源への応用

焦電結晶の小型高エネルギーX線源への応用

焦電結晶を用いてポータブルサイズかつ高エネルギーのX線源を製作し，発生するX線のエネルギーおよび時間当たりのX線強度を評価した．代表的な焦電結晶であるLiTaO3 単結晶を用い，条件や構造を変えて3つのX 線管を製作した．最も高いエネルギーのX線まで発生したさせたX線管では，これまでのところ3 V，1.2 Aの電源で80 keV 程度までのエネルギーのX 線が確認できた．また，この線源を用いて真鍮板の蛍光X 線スペクトルを測定し，Cu とZn の特性X線を確認できた．さらに試料を電子により励起することにより特性X線分析を考案した．この方法と蛍光X線分析を，真鍮板を試料として比較した結果，ZnのKβ線のピークをよりはっきり確認することができた．


Analysis of Valence for Chromate Conversion Coatings Using Laboratory XAFS Spectrometer and a Comparison with X-ray Photoelectron Spectroscopy

実験室系X線吸収分光分析装置を用いたクロメート皮膜中クロムの価数評価及びX線光電子スペクトルとの比較

We performed a nondestructive and in laboratory evaluation technique of hexavalent chromium (Cr(VI)) in chromate conversion coatings using a laboratory X-ray absorption fine structure (XAFS) spectrometer equipped with W anode X-ray tube. The recorded XANES spectrum of a chromate conversion coating sample with fluorescence mode possessed the Cr-K X-ray absorption edge. We have obtained calibration curves of the ratio of Cr(VI)/Cr(III) by the height of pre-edge peak and the Cr-K X-ray absorption edge energy of the reference samples prepared by Cr2O3 (Cr(III)) and CrO3 (Cr(VI)) particle reagents. The calibration curves showed the high correlation coefficients such as 1.00 for the height of pre-edge peak and 0.99 for the value of the energy on the Cr-K X-ray absorption edge. The ratio of Cr(VI)/Cr(III) in the chromate conversion coating has also been evaluated by the X-ray photoelectron spectroscopy (XPS) and 1,5-diphenyl-carbazide absorption spectrometry (DPC) methods. The ratio of Cr(VI)/Cr(III) evaluated by the laboratory XAFS spectrometer was almost identical to that by XPS method.


Stability of silver cluster in zeolite A and Y catalysts


Phosphate adsorption site on zirconium ion modified MgAl-layered double hydroxides


Pore-size dependence of the acidic property of mesoporous silica FSM-16


Analysis of Valence for Chromium in Soil and Plastic Samples Using Laboratory XAFS Spectrometer

実験室系X線吸収分光分析装置を用いる土壌及びプラスチック中クロムの価数評価

Hexavalent {Cr(VI)} and trivalent chromium {Cr(III)} in environmental materials such as soil and plastics were investigated using a laboratory X-ray absorption fine structure (XAFS) spectrometer equipped a W anode X-ray tube. The Cr-K X-ray absorption edges were observed on the XANES spectra of soil (total chromium 606 ppm) and plastic (213 ppm) samples with a fluorescence mode, while the signal-to-noise (SN) ratios of these spectra were too low to determine the height of pre-edge peak of Cr(VI) and the value of the energy on the Cr-K X-ray absorption edge. The XANES spectra of reference samples prepared by Cr2O3 {Cr(III)} and CrO3 {Cr(VI)} particle reagents were also recorded with the transmission mode. In order to improve the SN ratios of XANES spectra, a smoothing treatment by Savitzky-Golay method was applied to the XANES spectra of the soil and plastic samples. By the smoothing treatment, SN ratios of these spectra were improved, though the height of pre-edge peak on the XANES spectra of Cr(VI) reference sample had decreased less than 5%. The height of pre-edge peak and the value of the energy on the Cr-K X-ray absorption edge of soil and plastic samples were given by smoothed XANES spectra. Using the height of pre-edge peak and the value of the energy on the Cr-K X-ray absorption edge of reference samples, the ratios of Cr(VI)/Cr(III) on the soil and plastic samples were calculated.


Chemical effects on Lα/Lβ ratios of X-ray fluorescence spectra

蛍光X線スペクトルLα/Lβ強度比に対する化学結合効果の影響

XRF spectra of Bi compounds were measured by EDX and WDX (single/double-crystal) to evaluate chemical effects on Lα/Lβ ratios. Alteration of Lα/Lβ ratios among Bi compounds was 5% at a maximum and influence of chemical effects were smaller than that of physical effects, for instance, sample shape or resolution of measurement devices.

エネルギー分散型(EDX)，一結晶波長分散型(一結晶WDX)，二結晶波長分散型(二結晶WDX)の分解能の違う3 種類の蛍光X線分析装置を用いて，Bi 化合物の蛍光X線スペクトルを測定し，Lα /Lβ 強度比に対する化学結合効果の影響を調べた． Lα /Lβ 強度比は化合物によって最大でも5% 程度であり，化学結合効果よりも試料形状や測定装置の分解能などの物理的要因の影響の方が大きかった．


Spatially resolved x-ray fluorescence analysis with a pyroelectric X-ray emitter

A portable instrument for two-dimensional X-ray fluorescence imaging was assembled with an X-ray source using a pyroelectric crystal, which was driven by a 9-V dry battery, a Si-PIN detector, a slit, and pulse motors. Line scanning for a mug and a knife-edge-scan of an iron sheet were carried out using this spectrometer. The sensitivity of the spectrometer was sufficient for elemental analysis of a mug using a 1 mm(2) slit, and several elements, such as Co, Ni, Zn, Pb and Zr, were detected. The estimated spatial resolution using a 0.8-mm pinhole was 3.5 mm.


Structural analysis of tungsten-zirconium oxide catalyst by W K- and L1-edge XAFS


Relationship between dynamic change of copper and dioxin generation in various fly ash

Only limited information on the chemical forms of copper in municipal solid waste incinerator (MSWI) fly ash is available in the literature. Therefore, we performed in situ X-ray absorption near-edge spectroscopy (XANES) experiments involving two types of real fly ash to confirm the behavior of copper in fly ash at secondary formation temperatures for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). CuCl(2).3Cu(OH)(2) was detected in both fly ash types before heating experiments. Cupric compounds in real fly ash were reduced to cuprous compounds or elemental copper at approximately 200 degrees C. The changes in the Cu XANES spectra observed for the two fly ash samples were similar to those observed previously. We also examined the behavior of copper in model fly ash using SiO(2) to investigate the effect of supporting materials and copper content in fly ash on the dynamic changes of copper and amount of dioxins generated. There was little difference between the use of boron nitride (BN) and SiO(2) as a supporting material. The formation mechanisms of PCDDs and PCDFs in both of the model fly ash types were basically the same. Thus, we conclude that the dynamic change of copper in MSWI fly ash during heating is a commonly observed feature, and no simple relationship between the composition of fly ash and the amount of PCDD/PCDF generated or dynamic change of copper is apparent. The dynamic change of copper explained the generated amount and homologue distribution of PCDDs and PCDFs.


XAFS and XRD Analysis of Ceria-Zirconia Oxygen Storage Promoters for Automotive Catalysts


Chemical states of trace heavy metal in sewage sludge incineration ash by using x-ray absorption fine structure

In this study, the chemical states of chromium (Cr), arsenic (As), and selenium (Se) in sewage sludge incineration ash were determined by X-ray absorption fine structure (XAFS) spectroscopy. Sewage sludge incineration ash was sampled from several facilities, and XAFS measurements were carried out with a beam line BL01B1 at the SPring-8 facility. Cr K-edge X-ray absorption near-edge structure (XANES) spectra suggested that Cr compounds were predominantly speciated as Cr(III) and the fraction of Cr(VI) was very minor. Compared to the reference materials, Cr XANES spectra of the incineration ashes were similar to those of FeCr2O4, Cr(OH)3, and CaCr2O4. As K-edge XANES spectra indicated that As(V) compounds were present in incineration ashes. Because the chemical state of As in sewage sludge was As3+ in our previous study, we speculated that the chemical state of As changed into As(V) during the incineration process. According to Se K-edge XANES spectra, Se compounds were predominantly Se(IV), and a slight difference was observed in the chemical states amongst facilities using inorganic or organic coagulants in the dewatering process.


Evidence of a strained pore wall structure in mesoporous silica FSM-16 studied by X-ray absorption spectroscopy


Effectiveness of the template-ion exchange method for appearance of catalytic activity of Ni-MCM-41 for the ethene to propene reaction


Origin and Dynamics of Oxygen Storage/Release in an Ordered CeO2-ZrO2 Catalyst Studied by Time-Resolved XAFS Analysis


Determination of chemical state of mercury on activated carbon using XANES X-ray Absorption Fine Structure


One-electron reducibility of isolated copper oxide on alumina for selective NO-CO reaction


An experimental study on Fischer-Tropsch catalysis Implications for impact phenomena and nebular chemistry


Structure of low coverage Ni atoms on the TiO2(110) surface - Polarization dependent Total-Reflection Fluorescence EXAFS study -


The role of Fischer-Tropsch catalysis in the origin of methane-rich Titan


Dynamic change of copper in fly ash during de novo synthesis of dioxins

Although many researchers have reported that copper chloride is an important catalyst that generates relatively large amounts of dioxins in heat experiments involving model fly ash, details on the behavior of copper during the process are still unavailable. In this study, we used in situ XANES experiments involving one type of real fly ash, which originated from a municipal solid-waste incinerator (MSWI), and two fly ash models to investigate the behavior of copper in fly ash at temperatures that are suitable for de novo synthesis, which is the major formation route for dioxins during waste incineration and thermal processes. Cupric compounds in real fly ash and model fly ash A(CuCl2.2H2O + activated carbon (AC) + boron nitride (BN)) were reduced to cuprous compounds or elemental copper at low temperatures. The changes in the Cu XANES spectra of real fly ash were similar to those of model fly ash A and those of an oxychlorination catalyst. In model fly ash B (CuO + AC + KCl + BN), CuO did not vary dramatically in the temperature range studied. In this study, we found strong evidence that oxychlorination, the key mechanistic step in the formation of dioxins, occurred in both real MSWI and model fly ash.


Determination of chemical form of antimony in contaminated soil around a smelter using X-ray absorption fine structure

Only limited information is available about the behavior of antimony (Sb) in contaminated soils. However, understanding the behavior of Sb in contaminated soils is important, because the toxicity or solubility of this element depends on its chemical state. In this study, we investigated the levels of Sb and the chemical forms of Sb in the soil around a smelter using X-ray absorption fine structure (XAFS) spectra. The highest Sb concentration in the contaminated soil was 2900 mg/kg dry soil. According to Sb-K edge X-ray absorption near edge (XANE) spectra, the Sb in the soil was in the form of Sb(V) compounds. The similarity of extended XAFS (EXAFS) spectra suggests that Sb speciation was independent of the sampling site, which indicates that Sb or Sb2O3 emitted from the smelter was converted into Sb(V) compounds in the soil.


The effect of copper speciation on the formation of chlorinated aromatics on real municipal solid waste incinerator fly ash

A limited amount of information exists regarding the relationship between the chemical form of copper and the formation of chlorinated aromatics in fly ash. To understand the effects of the various forms of copper on the formation of chlorinated aromatics in real fly ash, we determined the chemical forms of copper present in various types of real fly ash using X-ray absorption near edge structure (XANES) and evaluated the relationship between the chemical forms of copper and the formation of chlorinated aromatics. Copper chloride hydroxide (CuCl2 x 3Cu(OH)2) and cuprous chloride (CuCl) were the predominant copper species found in real fly ash. Although pure cupric chloride (CuCl2) is known to be the most active catalyst for the formation of chlorinated aromatics under experimental conditions with synthetic fly ash, CuCl2 was not found in every real fly ash sample. The amount of copper chloride hydroxide was positively correlated with the formation of chlorinated aromatics in real fly ash and is, consequently, considered to be one of the key species involved in the formation of chlorinated aromatics.


Study on the thermal degradation of CeO2-ZrO2 solid solution by XAFS and XRD


Direct speciation of lead, zinc and antimony in fly ash from waste treatment facilities by XAFS spectroscopy


A new heterogeneous olefin metathesis catalyst composed of rhenium oxide and mesoporous alumina


Application of doniach diagram on valence transition in La0.9Eu0.1Ni2(Si1-xGex)2

To investigate the valence transition of Eu in the pseudo-binary compounds series, EuCu_2(Si_xGei_<1-x>)_2, measurements of the lattice constants, the X-ray absorption spectroscopy (XAS), the magnetic susceptibility, χ, the electric resistivity, ϱ, the thermoelectric power, S, and the specific heat, C, have been carried out. The antiferromagnetic order for the samples with 0 ≤ x ≤ 0.50, the temperatureinduced valence transition for the samples with 0.68 ≤ x ≤ 1.0 and the state with a high electronic specific heat coefficient for the samples having the intermediate range of x of the above two were observed. The plotting of the Neel temperature, T_N, and of the valence transition temperature, T_V, as the function of x is found to resemble very well to the Doniach diagram, giving an evidence of the competition of the two interactions, the one for the valence transition, the other for the magnetic order. The observation of the sign change of S near to the temperature T_V is found to be a new feature of Eu compounds.

Journal of the Physical Society of Japan


Structures and Acid-Base Properties of La/Al2O3 - Role of La Addition to Enhance Thermal Stability of γ-Al2O3


Intermediate valence state of La0.9Eu0.1Ni2(Si1-xGex)2 compounds

We examined the temperature dependence of the Eu valence in La_<0.9>Eu_<0.1>Ni_2(Si_<1-x>Ge_x)_2 by means of magnetic susceptibility measurements and X-ray absorption spectroscopy. It was found that the Eu ions are in the intermediate valence state for 0.2 ≤ x ≤ 0.8 and the Eu valence gradually varies with temperature. The results are compared with those of the concentrated EuNi_2(Si_<1-x>Ge_x)_2 compounds. The main factor in determining the Eu valence in both dilute and concentrated alloys is discussed.


An in situ temperature dependent IR, EPR and high resolution XANES study on the NO/Cu+-ZSM5 interaction


Structures and electronic properties of the catecholatoiron complexes in relation to catechol dioxygenases: chlorocatecholatoiron complexes are compared to the 3,5-di-tert-butylcatecholatoiron complex in the solid state and in solution

Chlorocatecholatoiron complexes, [Fe(TPA)(4Cl[bond]Cat)]BPh(4) and [Fe(TPA)(3Cl[bond]Cat)]BPh(4), (4Cl[bond]Cat and 3Cl[bond]Cat: 4- and 3-chlorocatecholates, respectively; TPA: tris(2-pyridylmethyl)amine) were isolated as intermediates for the oxygenative cleavage of chlorocatechols by nonheme iron complexes. Geometric structures of these complexes together with [Fe(TPA)(DTBC)]BPh(4) (DTBC: 3,5-di-tert-butylcatecholate) as reference were analyzed by X-ray absorption spectroscopy (EXAFS) in the solid state and in solution. Structure of the DTBC complex in the solid state was shown to be noticeably different from the other complexes as seen in the magnetic susceptibility and spectroscopic data. Electronic and magnetic properties of these complexes were studied by X-ray absorption (XANES), electronic (VIS) and ESR spectroscopies, and magnetic susceptibility. Electron transfer from the catecholate ligand to the Fe(III) center was indicated by the Fe[bond]K edge values in XANES spectra and by the LMCT bands in electronic spectra. Magnetic susceptibility and ESR data indicated that at low temperatures the complexes are in equilibrium between the low (S=1/2) and high-spin (S=5/2) ferric states with the latter component increasing with temperature. Remarkable differences between the spin states in solid and in solution were observed with the DTBC complex.


X-ray absorption fine structure analysis on local structure of CeO2-ZrO2 mixed oxides with the same composition ratio (Ce/Zr =1)


NO reduction with CO in the presence of O2 over Al2O3-supported and Cu-based catalyst


TiO2/SiO2 photocatalysts at low levels of loading Preparation, structure and photocatalysts

Journal of Photochemistry and Photobiology A: Chemistry


Local Structure of Framework Iron in Fe-Substituted Al-Mordenites by Fe K Edge XAFS


NO reduction with CO in the presence of O2 over Cu/Al2O3 (3) -Structural analysis of active species by means of XAFS and UV/VIS/NIR spectroscopies-


Photo-enhanced reduction of CO2 by H2 over Rh/TiO2 characterization of supported Rh species by means of infrared and X-ray absorption spectroscopy

Journal of Molecular Catalysis A: Chemical


Synthesis of Fe-substituted Al-mordenites by hydrothermal method


XANES study of Li-MgO and Li-La2O3-MgO catalysts for oxidative coupling of methane

To characterize the defect sites in the near-surface and bulk phase of Li-MgO and Li-La2O3-MgO, XANES at Mg K-edge and La L3-edge was applied. For Li-MgO, it can be suggested that Li doping at a low content (2.5 wt%) brings about the formation of defect species only in the near-surface. This is due to the localization of doped Li ions in the surface, and thus the catalytically active species containing [Li+ O-] type center exist in the surface region. After OCM reaction, the detect species are formed in the near-surface over MgO and Li-MgO. By addition of La2O3 to Li-MgO (La/(Mg+La)=0.25), the structural change during the reaction is almost suppressed in the surface. In addition, the Li-La2O3-MgO shows higher C2 selectivity than Li-MgO.


Local structure analyses of Ce0.5Zr0.5O2 mixed oxides by XAFS

Three types of CeO2-ZrO2 with the same composition (Ce/Zr = 1) were prepared by different methods, exhibited the different oxygen storage/release capacity (OSC). To investigate the relationship between the OSC and the local structure, the Ce and Zr K-edges XAFS spectra for these samples were measured. The features of Fourier transforms of these samples were different from each other. This suggested that the OSC was remarkably exerted by the local structure around Ce and Zr. The quantitative curve-fitting analysis of EXAFS was applied, and it was concluded that homogeneous Ce(0.5)Zr(0.5)O2 solid solution at atomic level exhibited the highest OSC among these CeO2-ZrO2 with the same composition (Ce/Zr = 1).


Structural analysis of La/Al2O3 catalysts by La K-edge XAFS

Structural analysis of La/Al2O3 catalyst materials was carried out by means of XRD and La K-edge XAFS. Influences of loading amounts and treatment temperature on the local structure around La were investigated. La atoms are supported on gamma-Al2O3 in a highly dispersed form when a loading amount is less than 0.2 mmol g(Al2O3)(-1), and structural transformation of the La species does not take place in the temperature ranges of 873-1273 K. La species of highly loaded catalysts start to change their structure from oxide-like form to the aluminate at 1073 K. Formation of LaAlO3 perovskite on the catalyst surface requires a concentration of La atoms above 0.5 mmol g(Al2O3)(-1) (7.5 wt% as La2O3).


Effect of calcium sulfate addition on the activity of the absorbent for dry fuel Gas desulfurization


Alumina-supported rare-earth oxides characterized by acid-catalyzed reactions and spectroscopic methods


Photooxidation of cyclohexane over alumina supported vanadium oxide catalyst.


Silica-supported ytterbium oxide characterized by spectroscopic methods and acid-catalyzed reactions


Silica-alumina-supported molybdena catalyst for propene metathesis


Structure of surface tantalate species and photo-oxidation of carbon monoxide over silica-supported tantalum oxide


Acidic property of FSM-16 (2) Generation of Lewis acid sites and catalysis


Generation of acid sites on silica-supported rare earth oxide catalysts Structural characterization and catalysis for -pinene isomerization


XAFS study of the structure of silica-supported ytterbium oxide catalyst


XAFS study of ytterbium complexes as new type Lewis acid catalysts


XAFS Study of Fe- and Mn- promoted sulfated zirconia


Structural analysis of iron and manganese species in iron- and manganese- promoted sulfated zirconia


XAFS Study on the structure of ytterbium(III) trifluoromethanesulfonates as a new type catalysts


Application of XANES spectra to supported catalysts


Performance of the YB66 soft-X-ray monochromator crystal at the Wiggler beamline of the UVSOR facility

Soft X-ray spectra have been measured using a pair of YB(66)(400) monochromator crystals at the double-crystal monochromator beamline BL7A of the UVSOR facility, where the wiggler radiation has a magnetic field of 4 T. Deformation of the YB(66) crystal due to heat load from the synchrotron radiation is almost negligible. The photon flux is about 10(8) photons s(-1) (100 mA)(-1) in the energy region 1.2-2 keV and the energy resolution is 0.7 +/- 0.1 eV around hnu = 1.5 keV. These results show that the YB(66) crystal is suitable for use as a monochromator crystal. Its application to soft X-ray spectroscopy is discussed.


Templating fabrication of platinum nanoparticles and nanowires using the confined mesoporous channels of FSM-16 -Their structural characterization and catalytic performances in water gas shift reaction-

Journal of Molecular Catalysis A: Chemical


A robust platinum carbonyl cluster anion [Pt3(CO)6]52- encapsulated in an ordered mesoporous channel of FSM-16: FTIR/EXAFS/TEM characterization and catalytic performance in the hydrogenation of ethene and 1, 3-butadiene.


XAFS characterization of platinum carbonyl clusters synthesized in the channel of mesoporous zeolite


Ship-in-bottle synthesis of Pt and Ru carbonyl clusters in NaY zeolite micropore and ordered mesoporous channels of FSM-16; XAFS/FTIR/TPD characterization and their catalytic behaviors

Studies in Surface Science and Catalysis


Ship-in-bottle synthesis of [Pt15(CO)30]2- encapsulated in ordered hexagonal mesoporous channels of FSM-16 and their effective catalysis in water-gas shift reaction:

Journal of the American Chemical Society


マルチプローブを用いた安定化ジルコニアの アニールによる結晶，局所構造への影響の研究


工業材料の同時定性・定量分析へのX線回折法の利用に関する研究(Ⅲ)

工業材料の同時定性・定量分析へのX線回折法の利用に関する研究(Ⅲ)

京都府中小企業技術センター技報

京都府中小企業技術センター技報


Application of ordered mesoporous silica materials to catalysis

規則性シリカメソ多孔体の触媒化学への応用