The present work has been devoted to the catalytic reduction of N2O by H2 with Pt/SiO2 catalysts at very low temperatures, such as 110oC, and their nanoparticle sizes have been determined by using H2-N2O titration, X-ray diffraction(XRD) and high-resolution transmission electron microscopy(HRTEM) measurements. A sample of 1.72% Pt/SiO2, which had been prepared by an ion exchange method, consisted of almost atomic levels of Pt nanoparticles with 1.16 nm that are very consistent with the HRTEM measurements, while a Pt/SiO2 catalyst possessing the same Pt amount via an incipient wetness technique did 13.5 nm particles as determined by the XRD measurements. These two catalysts showed a noticeable difference in the on-stream deN2O activity maintenance profiles at 110℃. This discrepancy was associated with the nanoparticle sizes, i.e., the Pt/SiO2 catalyst with the smaller particle size was much more active for the N2O reduction. When repeated measurements of the N2O reduction with the 1.16 nm Pt catalyst at 110oC were allowed, the catalyst deactivation occurred, depending somewhat on regeneration excursions.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 촉매제조
  2.2. H2-N2O titration에 의한 H2 흡착량 측정
  2.3. XRD 측정․분석
  2.4. H2에 의한 N2O 저온환원반응
 3. 결과 및 고찰
  3.1. Pt/SiO2 촉매의 나노입자크기 결정
  3.2. N2O 직접분해반응에 대한 Pt/SiO2 촉매의 활성
  3.3. Pt/SiO2 촉매상에서 H2에 의한 N2O 환원반응
 4. 결 론
 참 고 문 헌

• 김문현(대구대학교 환경공학과) | Moon Hyeon Kim (Department of Environmental Engineering, Daegu University) Corresponding author
• 김대환(대구대학교 환경공학과) | Dae Hwan Kim (Department of Environmental Engineering, Daegu University)