II. Structure of Perovskites 1982 A. Crystal Structure 1982 B. Nonstoichiometry in Perovskites 1983 1. Oxygen Nonstoichiometry 1983 2. Cation Nonstoichiometry 1984 C. Physical Properties 1985 D. Adsorption Properties 1986 1. CO and NO Adsorption 1986 2. Oxygen Adsorption 1987 E. Specific Surface and Porosity 1987 F. Thermal Stability in a Reducing Atmosphere 1989 III. Acid−Base and Redox Properties 1990 A. Acidity and Basicity 1990 B. Redox Processes 1991 1. Kinetics and Mechanisms 1992 2. Reduction−Oxidation Cycles 1993 C. Ion Mobility 1993 1. Oxygen Transport 1993 2. Cation Transport 1994 IV. Heterogeneous Catalysis 1995 A. Oxidation Reactions 1995 1. CO Oxidation 1995 2. Oxidation of Hydrocarbons 1996 B. Pollution Abatement 2001 1. NOx Decomposition 2001 2. Exhaust Treatment 2002 3. Stability 2004 C. Hydrogenation and Hydrogenolysis Reactions 2004 1. Hydrogenation of Carbon Oxides 2004 2. Hydrogenation and Hydrogenolysis Reactions 2006

Chemical structures and performance of perovskite oxides.

A review on highly ordered, vertically oriented TiO2 nanotube arrays: Fabrication, material properties, and solar energy applications

The infrared spectral performance of the N x O y species observed on oxide surfaces [N2O, NO−, NO, (NO)2, N2O3, NO+, NO2 − (different nitro and nitrito anions), NO2, N2O4, N2O5, NO2, and NO3 − (bridged, bidentate, and monodentate nitrates)] is considered. The spectra of related compounds (N2, H-, and C-containing nitrogen oxo species, C─N species, NH x species) are also briefly discussed. Some guidelines for spectral identification of N x O y adspecies are proposed and the transformation of the nitrogen oxo species on catalyst surfaces are regarded.

Identification of Neutral and Charged N x O y Surface Species by IR Spectroscopy

We have investigated carrier transport in a crystalline oxide semiconductor InGaO3(ZnO)5 using single-crystalline thin films. When carrier concentration is less than 2×1018cm−3, logarithm of electrical conductivity decreases in proportion to T−1∕4 and room-temperature Hall mobility was as low as ∼1cm2(Vs)−1. When carrier concentration was increased to 4×1018cm−3, the conduction mechanism changed to degenerate conduction and room-temperature Hall mobility was steeply increased to >10cm2(Vs)−1, showing metal–insulator transition behavior. These results are explained by percolation conduction over distribution of potential barriers formed around conduction band edge. The potential distribution is a consequence of potential modulation originating from random distribution of Ga3+ and Zn2+ ions in the crystal structure of InGaO3(ZnO)5.

Carrier transport in transparent oxide semiconductor with intrinsic structural randomness probed using single-crystalline InGaO3(ZnO)5 films

Since the early development of this technology in the 1970s, TiO2 constitutes the archetypical photocatalyst due to its relatively high efficiency, low cost and availability. However, during the last decade a considerable number of new photocatalytic materials, either semiconductor or not, have been proposed as potential substitutes of TiO2, particularly in the case of solar applications, for which this standard photocatalyst is not very suitable because of its wide band gap. Semiconductors based on cations with d0 configuration such Ta5+ or Nb5+, as well as oxides or nitrides of d10 elements such as Bi3+, In3+ or Ga3+ are among the most successful novel photocatalysts, but non-semiconductor solids like cation-interchanged zeolites also produce interesting results. In addition, some classical semiconductors like ZnO or CdS, initially discarded as a consequence of their poor stability under irradiation, have been reconsidered as feasible photocatalysts for particular applications. This growing body of data requires new analysis of the challenges and opportunities facing photocatalysis in order to assess which of the photoactive materials are best for each particular application. In this review, we summarize, with an historical perspective, the main achievements obtained with photocatalyst alternatives to TiO2 in the three main niches for this technology: water splitting for hydrogen production, decontamination and disinfection processes, and organic synthesis.

Development of alternative photocatalysts to TiO2: Challenges and opportunities

Relation between the amounts of chemisorbed and physisorbed water on metal oxides

Determination des isothermes d'adsorption et etude de la structure superficielle de TiO 2 par spectrometrie IR

Adsorption of benzene, toluene, and chlorobenzene on titanium dioxide

Perovskite-type (La 1-x Sr x )MnO 3 (0≤x≤0.3) was synthesized through the sol-gel process at low temperature (400 o to 500 o C). Poly(acrylic acid) (PAA) was used to make a gel from an aqueous solution of lanthanum, strontium, and manganese nitrates. The particle-diameter distribution of the manganites had a maximum value of 0.3 to 0.7 μm, and a specific surface area of about 17.5 to 23.5 m 2 /g

Synthesis of Perovskite‐Type (La1−xSrx)MnO3 (O X 0.3) at Low Temperature

The changes of structure and electronic state of copper ion species during the heat treatment of copper ion-exchanged ZSM-5 zeolite (CuZSM-5) as well as the interaction with CO molecules have been investigated by using various spectroscopic techniques such as infrared (IR) and emission spectroscopy (ES), electron spin resonance (ESR), and X-ray absorption fine structure (XAFS) consisting of a XANES (X-ray absorption near edge structure) and an EXAFS (extended X-ray absorption fine structure) and through the measurements of heat of adsorption and adsorption isotherm. About 70% of the divalent copper ions (Cu2+) exchanged in CuZSM-5 were found to be reduced to the monovalent copper ions (Cu+) during the heat treatment at 873 K in vacuo, the latter species having a linear or a planar coordination structure with a coordination number of 2 or 3 with respect to the nearest-neighboring oxygen atoms at a distance of 1.98 A. It was found from the ES data that the Cu+ species strongly interact with CO molecules at ...

Mahiko Nagao

Papers

Relation between the amounts of chemisorbed and physisorbed water on metal oxides

Adsorption of benzene, toluene, and chlorobenzene on titanium dioxide

Synthesis of Perovskite‐Type (La1−xSrx)MnO3 (O X 0.3) at Low Temperature

New Analysis of Oxidation State and Coordination Environment of Copper Ion-Exchanged in ZSM-5 Zeolite

Specific feature of copper ion-exchanged mordenite for dinitrogen adsorption at room temperature