TiO2- and SiO2-supported Co3O4, Pt and Co3O4-Pt catalysts have been studied for CO and C3H8 oxidations at temperatures less than 250℃ which is a lower limit of light-off temperatures to oxidize them during emission test cycles of gasoline-fueled automotives with TWCs (three-way catalytic converters) consisting mainly of Pt, Pd and Rh. All the catalysts after appropriate activation such as calcination at 350℃ and reduction at 400℃ exhibited significant dependence on both their preparation techniques and supports upon CO oxidation at chosen temperatures. A Pt/TiO2 catalyst prepared by using an ion-exchange method (IE) has much better activity for such CO oxidation because of smaller Pt nanoparticles, compared to a supported Pt obtained via an incipient wetness (IW). Supported Co3O4-only catalysts are very active for CO oxidation even at 100℃, but the use of TiO2 as a support and the IW technique give the best performances. These effects on supports and preparation methods were indicated for Co3O4-Pt catalysts. Based on activity profiles of CO oxidation at 100℃ over a physical mixture of supported Pt and Co3O4 after activation under different conditions, and typical light-off temperatures of CO and unburned hydrocarbons in common TWCs as tested for C3H8 oxidation at 250℃ with a Pt-exchanged SiO2 catalyst, this study may offer an useful approach to substitute Co3O4 for a part of platinum group metals, particularly Pt, thereby lowering the usage of the precious metals.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 촉매제조
  2.2. Co3O4 및 Pt 담지촉매들의 입자크기 결정
  2.3. CO/C3H8 산화반응
 3. 결과 및 고찰
  3.1. 저온 CO 산화반응에 대한 촉매담체의 영향
  3.2. 저온 CO 산화반응에 대한 촉매제조법의 영향
  3.3. 저온 CO 산화반응에 대한 전처리 조건의 영향
  3.4. C3O4-Pt 담지촉매상에서의 저온 CO 산화반응
  3.5. Pt/SiO2 촉매상에서의 저온 C3H8 산화반응
 4. 결 론
 참 고 문 헌

• 김문현(대구대학교 환경공학과) | Moon Hyeon Kim (Department of Environmental Engineering, Daegu University) Corresponding Author
• 김동우(대구대학교 환경공학과) | Dong Woo Kim (Department of Environmental Engineering, Daegu University)
• 함성원(경일대학교 화학공학과) | Sung-Won Ham (Department of Chemical Engineering, Kyungil University)