T. Yamaguchi

Bio: T. Yamaguchi is an academic researcher from Hokkaido University. The author has contributed to research in topics: Catalysis & Linguistics. The author has an hindex of 2, co-authored 2 publications receiving 293 citations.

Acid-base bifunctional catalysis by ZrO2 and its mixed oxides

Abstract: Examples of acid-base bifunctional catalysis by ZrO2 and its mixed oxides are summarized. The hydrogenation of olefins, carbon monoxide and aromatic carboxylic acids over ZrO2 are also examples of acid-base bifunctional catalysis which occur by heterolytic splitting of a hydrogen molecule (H2) into a proton (H+) and a hydride ion (H−) on the acid-base pair sites. Industrial applications of ZrO2 catalysts are demonstrated, the importance of acid-base bifunctional catalysis by ZrO2 and its mixed oxides being emphasized.

Olefin-aldehyde condensation reaction on solid acids

Abstract: A vapor phase octadiene synthesis from isobutyraldehyde and isobutene was examined over various catalysts at 523 K. Although solid bases were totally inactive, solid acids exhibited high activity to yield dienes. Niobic acid was found to be an excellent catalyst in the total yield. WO3/TiO2 and Ag-O/SiO2 were also excellent catalysts with respect to the diene selectivity (98–99%), though the yields were slightly lower than that of niobic acid. Acid strength required for the reaction was found to be in the range of −8.2 $ Ho ⩽ −3.0. Reactions from furan derivatives and octanol were also investigated.

Insertion of the voiceless fricative [s] at word-final position in Japanese English

Abstract: ABSTRACT This article explains how the voiceless fricative [s], or what we refer to as ‘special [s],’ occurs in free talk produced by Japanese speakers of English and what this means for the current understanding of Japanese English. The discussion is based on a small corpus compiled by the authors from recordings. The findings are threefold. The special [s] is always voiceless, occurs only word-finally, and arises from four different pragmatic forces. These forces are discourse marker, hesitation, cause and effect, and expression of self. The definition of Japanese English has been built heavily on the influence of the first language (L1) on the second language (L2). While L1 transfer is integral to L2 English production, the present article supplements this view by disclosing facts about what L2 users do while they are engaged in speaking in English; that is, in usage events.

English Produced by Japanese L2 Users

Abstract: A Study of Japanese English Grammar promotes a new understanding of non-native English norms and addresses issues relating to World Englishes

Chapter 5. Verbs of eating

Abstract: The chapter explains how kuu and taberu, two major verbs of eating in Japanese, emerged, developed, and changed their literal and figurative meanings. Both verbs began their life distinctly. Kuu emerged from the active zone, while societal structures gave rise to taberu. This difference is reflected in two facets of culture, labeled Culture 1 and Culture 2, which embrace adversity and hierarchical society, respectively, revealing two social attributes that are historically prevalent in Japan. Today’s usages of taberu and kuu show a shift in the selection of active zones and a shift from metonymy to metaphor. Drawing upon kuu’s current tendency to withdraw from figurative expression, the chapter suggests that metonymy and metaphor can effect a clear division of labor.

Catalysis and photocatalysis by metal organic frameworks

Abstract: Metal organic frameworks (MOFs) are a class of porous crystalline materials that feature a series of unique properties, such as large surface area and porosity, high content of transition metals, and possibility to be designed and modified after synthesis, that make these solids especially suitable as heterogeneous catalysts. The active sites can be coordinatively unsaturated metal ions, substituents at the organic linkers or guest species located inside the pores. The defects on the structure also create these open sites. The present review summarizes the current state of the art in the use of MOFs as solid catalysts according to the type of site, making special emphasis on the more recent strategies to increase the population of these active sites and tuning their activity, either by adapting the synthesis conditions or by post-synthetic modification. This review highlights those reports illustrating the synergy derived from the presence of more than one of these types of sites, leading to activation of a substrate by more than one site or to the simultaneous activation of different substrates by complementary sites. This synergy is frequently the main reason for the higher catalytic activity of MOFs compared to homogeneous catalysts or other alternative solid materials. Besides dark reactions, this review also summarizes the use of MOFs as photocatalysts emphasizing the uniqueness of these materials regarding adaptation of the linkers as light absorbers and metal exchange at the nodes to enhance photoinduced electron transfer, in comparison with conventional inorganic photocatalysts. This versatility and flexibility that is offered by MOFs to optimize their visible light photocatalytic activity explains the current interest in exploiting these materials for novel photocatalytic reactions, including hydrogen evolution and photocatalytic CO2 reduction.

Industrial application of solid acid–base catalysts

Abstract: A statistical survey of industrial processes using solid acid–base catalysts is presented. The number of processes such as alkylation, isomerization, amination, cracking, etherification, etc., and the catalysts such as zeolites, oxides, complex oxides, phosphates, ion-exchange resins, clays, etc., are 127 and 180, respectively. The classification of the types of catalysts into solid acid, solid base, and solid acid–base bifunctional catalysts gives the numbers as 103, 10 and 14, respectively. Some significant examples are described more in detail. On the basis of the survey, the future trend of solid acid–base catalysis and the fundamental research promising for industrial success are discussed.

Self-ordering electrochemistry: a review on growth and functionality of TiO2nanotubes and other self-aligned MOx structures

Abstract: Among all one dimensional nanostructures other than carbon, titania nanotubes have gained increasingly more scientific interest due to a successful combination of functional material properties with a well controllable nano-architecture. For self-organized TiO2nanotube arrays not only the simple increase in the specific surface area but also their self-aligned nature leads to a significant enhancement of the performance when used in photoelectrochemistry, photocatalysis, dye-sensitized solar cells, or electrochromic devices. In addition to this, these ordered and size-controlled nanostructured TiO2 surfaces also have material-specific advantages, for example in superhydrophobic/superhydrophilic and biomedical applications. The formation of these vertically oriented nanotube arrays can be achieved by a simple one-step electrochemical self-assembly process. By adjusting the anodization parameters, the geometry such as the tube length or diameter can easily be controlled. The present review addresses the formation, properties and applications not only of TiO2nanotubes but also of related transition metal oxides.

Application of ZrO2 as a catalyst and a catalyst support

Abstract: Examples of the application of ZrO 2 for catalysts and catalyst supports are reviewed. The specificity of the structure and the surface properties including the behavior of surface OH groups are introduced. The catalytic properties of dispersed and promoted ZrO 2 are presented. The novel application to the photocatalytic total decomposition of water is also presented.