#################################################### # Hyunjung Kim # requesting 7 days, at minimum=5 days # beamline 34ID-C, Mapping of deformation field of CdS dots in Zeolite microcrystals # instrument 34ID-C coherent #################################################### # top:/home/www/beamtime-requests/req01247.txt # UNICAT Member Beam Time Request #1247 # created Mon Sep 08 06:35:50 CDT 2008 #################################################### apsrun: 2008-03 beamline: 34ID-C collaboration: Yes 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. We will prepare bare ZSM5 and Cu exchanged ZSM5 zeolites. The sample sizes are 2-8 micrometers and are attached on a Silicon substrate. In order to get strains developed along the process of catalytic decomposition (in Cu-ZSM5) with NO gas, Coherent X-ray Diffraction measurements will be carried out in the controlled environment with gas concentration. The temperature will be varied from room temperature to 500C and NO, C3H6, O2 gas concentration will be varied. The sample cell with temperature control will be brought to the beamline. Each measurement takes four to five hours for one direction and several measurements with rotating samples need to be taken for three dimensional images. equipment_required: experiment: Mapping of deformation field of CdS dots in Zeolite microcrystals foreign_nationals: hazards: Gas inlet with flow control needed. The three kinds of gases, NO, O2 and C3H6 will be needed. instrument: 34ID-C coherent instrument_other: minimumdays: 5 name: Hyunjung Kim nonmembers: submit: Submit unacceptable_dates: I prefer the dates from Dec. 5-11. z34ID_change_undulator: yes z34ID_details: z34ID_parasitic: yes #REMOTE_HOST: unknown: Host 155.74.92.210.in-addr.arpa not found: 3(NXDOMAIN) child process exited abnormally #REMOTE_ADDR: 210.92.74.155 #CONTENT_LENGTH: 2868 #HTTP_REFERER: http://www.uni.aps.anl.gov/admin/unireq.html #HTTP_USER_AGENT: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; BESAGENT; .NET CLR 1.1.4322; BESAGENT)