Showing papers by "Atsushi Takahashi published in 2007"

Terminal board for control panel test, control panel automatic testing device, and temporary control device

Abstract: PROBLEM TO BE SOLVED: To provide a terminal board for a nuclear power plant control panel test, a control panel automatic testing device, and a temporary control device, which reduces a time and cost by reducing a work amount during updating, and also reduces an operation risk caused by plant monitoring control function stop. SOLUTION: This terminal board for the control panel test, detachably fixed to a terminal board installed on a control panel when updating a control unit of the control panel, is equipped with: an elongation terminal to be conducted and opened electrically to a terminal of the terminal board; a fixing metal to be fixed to the terminal board; an external apparatus connection cable to be connected to an external apparatus; and an external apparatus interface part. COPYRIGHT: (C)2008,JPO&INPIT

Reaction properties of NO and CO over an Ir(211) surface

Abstract: The adsorption and thermal reactivity of NO and CO over an Ir(211) surface were studied using x-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, and temperature-programed desorption. NO adsorbed on the atop site of the (111) terrace and the bridge site of the (100) step at 273K. In contrast, CO adsorbed only on the atop site at 273K, initially on the (111) terrace and then on the (100) step. Both atop NO and bridge NO decomposed to N2 through the recombination of atomic nitrogen, indicating that the Ir(211) surface provides high NO dissociation activity. When NO and CO were coadsorbed, the preadsorption of atop CO on the terrace sites selectively inhibited the adsorption of atop NO on the terrace sites, while preadsorption of atop CO on the step sites significantly inhibited the adsorption of bridge NO on the step sites. These results indicate that NO may be selectively reduced by CO in the presence of O2 when Ir(211) is used as the catalyst.

Selective reduction of NO2 with acetaldehyde over Co/Al2O3 in lean conditions

Abstract: Selective reduction of NO 2 with acetaldehyde (CH 3 CHO) was investigated over alumina-supported catalysts. Among the catalysts tested, Co/Al 2 O 3 showed the highest activity with a maximum performance at 2 wt.% Co loading. The comparison of the activity of Co/Al 2 O 3 and Al 2 O 3 for several unit reactions suggested that one of the roles of supported Co is to suppress the combustion of CH 3 CHO by O 2 , resulting in an enhancement of the selective reaction of CH 3 CHO with NO 2 . The observation of the adsorbed species by in situ FT-IR spectroscopy showed that enolate species acts as the intermediate for NO 2 reduction by CH 3 CHO and that another role of Co is to promote the production of the enolate species.

Enhancing Effect of H2 on the Selective Reduction of NO with CO over Ba-doped Ir/WO3/SiO2 Catalyst

Abstract: In order to improve the catalytic performance of supported-Ir catalysts for the selective reduction of NO with CO, the effect of H2 was investigated. While adding H2 showed no or negative effect on NO conversion on Ir/SiO2, Ba/Ir/SiO2 and Ir/WO3/SiO2 catalysts, the activity of Ba-doped Ir/WO3/SiO2 catalyst for NO reduction was significantly increased by H2 addition. The role of H2 was found to stabilize the catalytically active Ir-WOx sites during the reaction.

Catalytic Performance of Monolithic Ir/SiO2 Based Catalysts for Selective Reduction of NO with CO

Abstract: 我々のグループは，これまで一酸化炭素を還元剤とする一酸化窒素選択還元触媒反応において，Ir/SiO2触媒およびタングステン，バリウムを添加した改良触媒（Ir/WO3-SiO2，Ba/Ir/WO3-SiO2）が高い活性を示すことを報告してきた。しかし，いずれも粉体触媒を用いた検討であり，その結果から各触媒の実用性能を比較し応用を考えるのは難しい。そこで，これらの触媒をモノリス状に調製し，活性，耐久性を検討した。 モノリス状の各触媒についてモデル排ガスを用いて200℃から600℃の間で昇降温を繰り返し活性試験を行ったところ，いずれの触媒も最初の昇温過程では活性が低いがそれに続く降温過程以降では高い活性を示し，反応の繰返しにより徐々に最適反応温度が高温化するとともに活性が低下した。粉体触媒の結果と比較すると，いずれの触媒も最高活性温度，CO酸化温度とも大幅に高温化し，特にタングステンを添加した触媒でその影響が大きかった。単位触媒重量あたりのガス処理量の増加やモノリス化による熱·物質移動の変化により差異がでたと推定された。一方，繰返し試験後の触媒活性序列と触媒劣化の速度は粉体触媒の結果と関連づけられた。劣化後の触媒ではいずれもIrO2の生成が確認され，還元再生できたので，劣化原因はイリジウムの酸化によると考えられた。Ba/Ir/WO3-SiO2が最も高い性能を示し，Ir金属の分散度が高くかつIr金属の耐酸化性が高いことが見出された。SO2が共存しない反応ガスを用いた反応試験において，酸化タングステンを含む担体を有する触媒ではSO2の影響は少ないが，Ir/SiO2触媒では大きな影響があることが確認された。

Catalyst for deoxidizing nitrogen oxide selectively

Abstract: PROBLEM TO BE SOLVED: To provide a catalyst exhibiting high activity stably over a long period of time under a wide reaction condition such as temperature and space velocity when used for deoxidizing NOx contained in exhaust gas in an oxygen-excess atmosphere by using CO. SOLUTION: The catalyst for deoxidizing nitrogen oxides selectively in the presence of oxygen by using carbon monoxide is obtained by depositing iridium and one or more metals selected from metals of group I, group II, group III, group IX, group XI and group XII in the periodic table on a carrier consisting of tungsten oxide and silica. COPYRIGHT: (C)2007,JPO&INPIT