Volume 42 Number 1 (2011.3)
Special Feature
Automotive Exhaust Catalyst
Part I. Special Feature
Overview
Review
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pages 1-8
Hirofumi Shinjoh
Noble metal sintering on a three-way catalyst was suppressed by the anchoring effect of the support. A catalyst with Pt and Rh loaded on ceria-based and zirconia-based supports, respectively, was developed. The catalytic activity was far superior to conventional catalysts, but with a lower noble metal content.
Research Reports
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3. NOx Storage and Reduction Catalysts for Gasoline-fueled Automotive Exhaust
(189kB)pages 9-19
Naoki Takahashi
This report reviews nitrogen oxide storage and reduction reactions and the technologies used by the Toyota group alliance to improve the durability of NOx storage and reduction type catalysts for gasoline fueled automotive lean-burn engines against both thermal damage and sulfur poisoning.
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pages 21-32
Masaoki Iwasaki
Development and characterization of Fe/zeolites, and reaction analyses were conducted for NH3-SCR of NOx. The effects of Fe loading (preparation method and Fe content) and the pore structure and Si/Al2 ratio of the zeolite species were investigated. NO2 adsorption/desorption behavior, elementary SCR kinetics and the reaction mechanism were also investigated.
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pages 33-42
Takafumi Yamauchi, Shuichi Kubo, Tomohito Mizukami, Noboru Sato, Norihiko Aono
A micro-kinetic reaction model was developed with consideration of the gas diffusion inside the washcoat for the development of multifunctional catalysts. Numerical simulation was conducted for various coating types of three-way catalysts under Federal Test Procedure (FTP) conditions. It was found that the double-layered-catalyst had a significant advantage, especially with respect to NOx emissions. It was concluded that the numerical simulation with detailed chemistry was effective for optimization of the catalyst design.
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6. In Situ Redispersion of Platinum Supported on Ceria-based Oxide for Automotive Catalysts
(1,060kB)pages 43-50
Yasutaka Nagai
Efficient redispersion was observed in Pt/ceria-based oxide catalysts for autoexhaust applications using in situ, time resolved, X-ray absorption spectroscopy (XAS), where large Pt agglomerates on a ceria-based oxide support split into smaller particles during rapid (ca. 60 seconds) redox cycling.
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pages 51-62
Yoshihide Watanabe, Noritake Isomura, Hirohito Hirata, Xingyang Wu
We investigated size-selected Ptn (n = 4, 7-10, 15) clusters deposited on TiO2(110). The catalytic activities had a cluster size dependency under conditions close to those in practical uses. Clusters smaller than Pt7 lay flat on the surface with a planar structure, and a planar-to-three-dimensional transition occurred at n = 8 for the Ptn clusters.
Part II. Highlighted Papers
Review
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8. Luminescent Periodic Mesoporous Organosilicas
(480kB)pages 63-69
Takao Tani, Norihiro Mizoshita, Shinji Inagaki
Periodic mesoporous organosilicas (PMOs), which were first developed in our company, are a new class of functional materials having a hybrid framework and ordered mesochannels. Various functionalities can be incorporated into the framework by proper designs of the bridging organic groups. This review highlights on recent progress in the development of PMOs bearing luminescent organic groups.
Research Reports
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pages 71-81
Tomohiko Jimbo, Yoshikazu Hayakawa
The present paper describes a model representation of multi-cyclic phenomena for a multi-cylinder engine system. The concept of role state variables is proposed to transform the derived periodically time-varying model into a time-invariant one. The stabilizability of the time-invariant model implies that of the periodically one. The time-invariant model is used to design cold start controllers.
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pages 83-89
Nobuhiro Ishida, Tomiko M. Suzuki, Toru Ohnishi
Poly D-lactic acid has attracted attention as valuable polymer for improving the thermostability of poly lactic acid through stereo-complex formation. In this study, we developed a metabolically engineered yeast strain that is able to efficiently produce D-lactic acid monomer with high optical purity.
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11. Reactively Steered Ring Antenna Array for Automotive Application
(511kB)pages 91-98
Shinya Sugiura, Hideo Iizuka
This paper proposes a novel type of smart antenna, which features a conformal configuration with three overlapping one-wavelength ring elements. Its directivity can be controlled by changing the values of variable reactance circuits that are embedded in the antenna. The antenna can be mounted on the windshield of an automobile without interfering with the view of the driver.