Monitoring the Activation of Copper-Containing Zeotype Catalysts Prepared by Direct Synthesis Using in Situ Synchrotron Infrared Microcrystal Spectroscopy and Complementary Techniques

Eike C. V. Eschenroeder, Alessandro Turrina, A. Lorena Picone, Gianfelice Cinque, Mark D. Frogley, Paul A. Cox, Russell F. Howe, Paul A. Wright*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The use of copper polyamine complexes as structure directing agents for microporous solids offers a direct route to the inclusion of Cu2+ complex cations in their pores: upon calcination, this gives active catalysts for the selective catalytic reduction of NO with NH3. In situ synchrotron IR absorption spectroscopy on crystals of dimensions 25-35 mu m has, been used to monitor the dehydration of the Cu2+-cyclam complex that acts as a cotemplate for the silicoaluminophosphate SAPO STA-7 and, at higher temperatures (400 degrees C), the calcination that gives the active catalyst Cu,H-SAPO STA-7. Polarized synchrotron IR microspectroscopy reveals strong alignment of N-H bonds of the Cu2+ cyclam in the larger cages of as-prepared STA-7, and complementary X-ray diffraction, ESR, UV-visible spectroscopy, and computer simulation indicate that the hydrated complex acts as cotemplate during crystallization: dehydration leads to removal of its coordinated water by 200 degrees C.

Original languageEnglish
Pages (from-to)1434-1441
Number of pages8
JournalChemistry of Materials
Volume26
Issue number3
Early online date29 Dec 2013
DOIs
Publication statusPublished - 11 Feb 2014

Keywords

  • silicoaluminophosphate molecular-sieves
  • exchanged ZSM-5 zeolites
  • methanol-to-olefin
  • nitrogen monoxide
  • active-sites
  • SAPO STA-7
  • reduction
  • decomposition
  • crystals
  • NOX

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