Selective catalytic reduction of NOx with NH3 over short-range ordered W-O-Fe structures with high thermal stability

Ying Xin, Nana Zhang, Qian Li, Zhaoliang Zhang* (Corresponding Author), Xiaoming Cao, Lirong Zheng, Yuewu Zeng, James A. Anderson (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticle

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Abstract

The selective catalytic reduction (SCR) of NOx with NH3 was studied over poorly-crystalline W-Fe composite oxides (WaFeOx). The short-range order present within the W-O-Fe structure was found to be responsible for the excellent SCR activity, in which the strong atomic-level interaction between Fe and W atoms promoted the formation of both Lewis and Brønsted acidity. The W-O-Fe structure existed as amorphous overlayers, approximately 2 nm thick over the surface of crystalline particles after high-temperature aging as shown by high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). After treatment at 800oC for 5 h, the WaFeOx catalysts still showed almost 100% NO conversion in the range 300-450oC with 100% N2 selectivity, despite the loss in surface area. This resistance to the impacts of high temperature ageing guarantees high activity of SCR catalysts which often suffer during high-temperature excursions as in the case of diesel exhaust due to diesel particulate filter (DPF) regeneration.
Original languageEnglish
Pages (from-to)81-87
Number of pages7
JournalApplied Catalysis B: Environmental
Volume229
Early online date9 Feb 2018
DOIs
Publication statusPublished - 5 Aug 2018

Keywords

  • Nitrogen oxides
  • Selective catalytic reduction
  • Ammonia
  • Short-range order
  • High thermal stability
  • IRON TITANATE CATALYST
  • TI AMORPHOUS OXIDES
  • IN-SITU IR
  • NITRIC-OXIDE
  • TEMPERATURE-RANGE
  • CE/TIO2 CATALYST
  • ACTIVE-SITES
  • MIXED OXIDES
  • THE-ART
  • AMMONIA

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