####################################################
# Hyunjung Kim <hkim@sogang.ac.kr>
# requesting 7 days, at minimum=5 days
# beamline 34ID-C, Catalytic Decomposition and Selective Reduction Mechanism in Zeolites: In situ Coherent X-ray Diffraction Study
# instrument 34ID-C coherent
####################################################
# top:/home/www/beamtime-requests/req01166.txt
# UNICAT Member Beam Time Request  #1166
# created Wed Aug 22 10:36:49 CDT 2007
####################################################

apsrun:
	2007-03

beamline:
	34ID-C

collaboration:
	Yes

collaborator_Paul:
	ON

contact:
	hkim@sogang.ac.kr

days:
	7

description:
	The synthetic zeolites are well-known as catalysts or adsorbents in various chemical reactions and separation processes. In particular, great attention has been given to the zeolitic molecular sieves containing transition metal ions. It is notable that a copper ion-exchanged zeolite has been reported to be a useful substance as the catalyst for the decomposition of nitrogen oxides (NOx). An understanding of the catalytic mechanism of NOx reduction is critical for the development of next-generation high-fuel efficiency, low-emission vehicles. After the specific properties of copper ion-exchanged ZSM-5-type zeolite for NOx decomposition have been found, this substance attracts a great deal of attention of scientists and the subject related to this phenomenon has been widely examined. Over the past few decades a considerable number of studies have been investigated by X-ray powder diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Many studies show that the monovalent copper ion exchanged in zeolite is responsible for the NOx decomposition reaction, though the problem is still in controversy. Although the poor hydrothermal stability seems to hamper its practical applications, Cu-ZSM-5 has been extensively studied as a “model system”. In this beamtime, we propose to study the catalytic decomposition in metal exchanged zeolites and the reaction with water/liquids in pure zeolites which might cause strains in the crystals. [It is an extension of GUP-8192 (the rating = 1.7)]. The samples will be in a UHV chamber to measure the internal structural changes by in situ coherent x-ray diffraction (CXD) with increasing e.g., NO gas concentration as a function of temperature, and reactions with water and other liquids. The zeolite Y and Cu-ZSM5 will be measured along the process of water/liquid reaction and catalytic decomposition, respectively.

equipment_required:
	UHV Chamber

experiment:
	Catalytic Decomposition and Selective Reduction Mechanism in Zeolites: In situ Coherent X-ray Diffraction Study

foreign_nationals:
	Hyunjung Kim, Younsuk Byun

hazards:
	

instrument:
	34ID-C coherent

instrument_other:
	

minimumdays:
	5

name:
	Hyunjung Kim

nonmembers:
	

submit:
	Submit

unacceptable_dates:
	

z34ID_change_undulator:
	yes

z34ID_details:
	

z34ID_parasitic:
	no


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