Effects of cooling mode and the poisoning of pb and P on the activity of perovskites for toluene oxidation

• Main Authors: Tan Kean Seng, 陳建生
• Other Authors: Professor Hung-Shan Weng
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/94146969154030936633

碩士 === 國立成功大學 === 化學工程研究所 === 82 === Perovskite-type catalysts are able to catalyze both reduc- tion and oxidation that make it possible to be treated as three- way catalysts. To simulate the poisoning environment of three- way catalytic converter in the automobile engine for the poison- ing of the perovskite, we used a Pulse-Flame reactor to proceed the lead and phosphorus poisoning of the catalysts. The activi- ties of catalysts before and after poisoned were monitored by the oxidation of toluene. After poisoning, the catalysts La0.3 Sr0.7CoO3 and SrCoO3 showed large increment in their activities while others showed little increment or even decrement on their activities. When using ICP to analyze the amount of lead adsorb- ed on the surface of catalysts, we found that the amount of lead adsorbed on the surface of manganate-based catalysts were pro- portional to the amount of Sr substitution and the specific sur- face area of catalysts. However, cobalt- based catalysts did not follow these rules. The amount of cobalt with the valence state of +3 in the catalysts became larger after poisoning when ana- lyzed with SIMS. We also investigated the surface component of La0.3Sr0.7CoO3 with ESCA, we found that the O 1s spectra of this poisoned catalyst has a high energy BE shifting to 535 +- 0.5eV. This might be due to the carbonate ion bound in the catalysts. (the following is omitted)