Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.35, No.4, 565-572, 1997
고정원배가스에서 SOx존재하에서의 NOx제거를 위한 Lanthanoid계 Perovskite형 촉매의 연구
The Studies on the Lanthaniod Perovskite Type Catalysts to Remove NOx under SOx Existence from Stationary Sources
ABO3형태의 Perovskite계열 복합 산화물 촉매를 사용하여 SCR공정(Selective Catalytic Reduction Process)에서 프로필렌을 환원제로 사용하여 SOx존재하에서의 NOx제거 활성을 조사하여 보았다. LaCoO3촉매는 NO제거 활성이 A site에 Ce이 40%치환되었을 때, 최고의 활성을 나타내었으며 B site에는 60%의 Fe을 부분 치환하였을 경우 저온(250-350℃)에서의 활성이 약간 떨어지나 비교적 넓은 온도범위에서 NOx제거 활성을 확보할 수 있었다. 또한 이는 전체적인 NOx제거 활성 결과와 산소결함(oxygen vacancy)측정 결과와 선형적으로 비례함을 얻을 수 있었고 이로부터 Perovskite형 촉매의 반응원리를 산소결함량과 연관하여 설명할 수 있었다.
Mixed oxide catalysts of ABO3 type Lanthanoid Perovskite have been investigated to remove NOx under SOx existence in SCR(Selective Catalytic Reduction) process using propylene as a reducing agent. When the catalyst was substituted 40% of A site by Ce, it showed the maximum activity for LaCoO3 catalyst. Substitution of B site in LaCoO3 with Fe 60% partially resulted in activity decrease in the range of low temperatures(250-350℃), but there were significant NOx reduction activities in the wide range of reaction temperature. It was found that NOx reduction activities were linearly correlated with oxygen vacancies of catalysts, and therefore the reaction principles of Perovskite catalyst employed in this work were well elucidated by the theory of oxygen vacancy.
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