DETERMINATION OF OXYGEN ACTIVITY IN OXIDE CATALYSTS IN NONEQUILIBRIUM GAS MIXTURES BY A MICROBALANCE TECHNIQUE
| Project/Area Number |
06453113
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業物理化学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
MIZUSAKI Junichiro Tohoku University, Research Institute for Scientific Measurements.Professor, 科学計測研究所, 教授 (90092345)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAMURA Ken-ichi Tohoku University, Research Institute for Scientific Measurements.Research Assoc, 科学測定研究所, 助手 (50270830)
NIGARA Yutaka Tohoku University, Research Institute for Scientific Measurements.Lecturer, 科学計測研究所, 講師 (90006148)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1995: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1994: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | metallic oxides / nonstoichiometry / surface reaction / oxide catalyst / carbon monoxide oxidation kinetics / nitrogen oxide decomposition kinetics / carbon monoxide sensor / nitrogen oxide sensor / CO酸化機構 / NOx分解機構 / COセンサー / NOxセンサー / 非平衡ガスの緩和 / NOXセンサー / 酸素不定比性 / 酸化物の酸素活量 |
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| Research Abstract |
This research aimed to measure the change in oxygen content of oxide catalysts under the steady-state catalytic reaction taking place on their surface. The catalysts considered were perovskite-type cobaltites, ferrites, cuprites and titanates, and the catalytic reaction considered was a redox reaction of trace amount of carbon monoxide and nitrogen oxide in oxygen rich atmospheres. In the proposed research plan prepared at Yokohama National University, a high temperature microbalance technique was considered as an only mean of the measurement. However, at the starting period of this project, the head investigator moved from YNU to the present institution and the technical know how of the use of nitrogen oxides and the utilities for the high temperature microbalance technique available at YNU turned to be the subject for reconstruction.
With this drastic variation of the circumstance, the research plan was revised : The conductivity variation with NOx gas in oxygen atmosphere was to be p
… More
roceeded at YNU with a mutual collaboration of Professor Tagawa of YUN.A microbalance system was to be constructed at Tohoku Univ.to study the weight change of the catalysts under the oxidation of carbon monoxide in oxygen rich atmosphere.
The research based on the conductivity measurements revealed that the conductivity enhancement by the nitrogen dioxide gas in oxygen atmosphere is attributed to the enrichment of nonstoichiometric oxygen in the bulk of the catalysts. New concept of "the effective oxygen chemical potential of nonequilibrium gas" was introduced.
The high temperature microbalance study revealed that the carbon monoxide in oxygen atmosphere causes the reduction of the catalysts to the extent much larger than the one corresponding to the oxygen partial change expected by the stoichiometric oxidation of carbon monoxide. Here, the nonequilibrium carbon monoxideoxygen gas mixtures was said to produce in the catalysts an "effective oxygen chemical potential" lower than the oxygen potential in the gas phase. Less
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Report
(3 results)
Research Products
(8 results)
