Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Microstructural property and catalytic activity of nano-sized MnOx-CeO2/TiO2 for NH3-SCR

선택적 촉매 환원법 재료로서 나노 사이즈 MnOx-CeO2/TiO2 촉매에 대한 미세 구조적 특성과 촉매활성 평가

  • Hwang, Sungchul (Graduate School of Convergence Science, Pusan National University) ;
  • Jo, Seung-hyeon (School of Materials Science and Engineering, Pusan National University) ;
  • Shin, Min-Chul (Material & Components Technology Center, Korea Testing Laboratory) ;
  • Cha, Jinseon (Material & Components Technology Center, Korea Testing Laboratory) ;
  • Lee, Inwon (Global Core Research Center for Ships and Offshore Plants, Pusan National University) ;
  • Park, Hyun (Global Core Research Center for Ships and Offshore Plants, Pusan National University) ;
  • Lee, Heesoo (School of Materials Science and Engineering, Pusan National University)
  • 황성철 (부산대학교 하이브리드 소재솔루션 협동과정) ;
  • 조승현 (부산대학교 재료공학부) ;
  • 신민철 (한국산업기술시험원 재료부품기술센터) ;
  • 차진선 (한국산업기술시험원 재료부품기술센터) ;
  • 이인원 (부산대학교 조선해양플랜트글로벌핵심연구센터) ;
  • 박현 (부산대학교 조선해양플랜트글로벌핵심연구센터) ;
  • 이희수 (부산대학교 재료공학부)
  • Received : 2016.02.23
  • Accepted : 2016.05.13
  • Published : 2016.06.30
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Abstract

$CeO_2$ is used as a co-catalyst with $TiO_2$ to improve the catalytic activity of $MnO_x$ and characterization of nano-sized powder is identified with de-NOx efficiency. A comparison between $MnO_x-CeO_2/TiO_2$ and single $CeO_2$ was conducted in terms of microstructural analysis to observe the behavior of $CeO_2$ in the ternary catalyst. The $MnO_x-CeO_2/TiO_2$ catalyst was synthesized by sol-gel method and the average particle size of the single $CeO_2$ is about $285{\mu}m$ due to the low thermal stability, whereas the particle size $MnO_x-CeO_2/TiO_2$ is about 130 nm. The strong interaction between Ce and Ti was identified through the EDS mapping by transmission electron microscopy (TEM). The improvement about 20 % of $de-NO_x$ efficiency is observed in the low-temperature ($150^{\circ}C{\sim}250^{\circ}C$) and vigorous oxygen exchange by well-dispersed $CeO_2$ is the reason of catalytic activity improvement.

저온용 SCR 촉매인 $MnO_x$의 촉매 활성을 높이기 위해 $TiO_2$ 지지체와 함께 조촉매로서 $CeO_2$을 사용하였고, 제조된 나노 사이즈의 촉매 특성과 함께 질소산화물 제거 효율에 대해 고찰하였다. $MnO_x-CeO_2/TiO_2$ 촉매 내에서 $CeO_2$ 거동을 확인하기 위해 단일 조성의 $CeO_2$와의 차이점을 미세구조적으로 비교 분석하였다. $MnO_x-CeO_2/TiO_2$ 촉매가 졸겔법을 통해 제조되었으며 낮은 열적 특성으로 인해 평균 $285{\mu}m$ 정도의 큰 입도를 가진 단일 $CeO_2$와는 달리 Ti 지지체와 함께 합성된 촉매의 경우 130 nm 정도로 줄어들었음을 확인하였다. 투과 전자 현경을 이용한 EDS mapping를 통해 Ce-Ti의 강한 interaction이 nano-sized powder 제조의 원인인 것으로 확인하였다. 조촉매 첨가로 인해 $MnO_x/TiO_2$ 촉매에 비해 저온영역에서 20 % 이상의 효율 향상이 있었으며 이는 3성분계 촉매 내에서 $CeO_2$가 나노 사이즈로 잘 분산됨에 따라 촉매 반응에 필요한 산소이온의 교환이 활발히 일어날 수 있었기 때문이다.

Keywords

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