Sökning: id:"swepub:oai:research.chalmers.se:45ade797-5849-4a0a-a2ce-4884a25c49c0" >
Characterization of...
Characterization of Active Species in Cu-Beta Zeolite by Temperature-Programmed Reduction Mass Spectrometry (TPR-MS)
-
- Li, J. H. (författare)
- Cummins Inc.
-
- Wilken, Norman, 1983 (författare)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Kamasamudram, K. (författare)
- Cummins Inc.
-
visa fler...
-
- Currier, N. W. (författare)
- Cummins Inc.
-
- Olsson, Louise, 1974 (författare)
- Chalmers tekniska högskola,Chalmers University of Technology
-
- Yezerets, A. (författare)
- Cummins Inc.
-
visa färre...
-
Cummins Inc Chalmers tekniska högskola (creator_code:org_t)
- 2013-04-03
- 2013
- Engelska.
-
Ingår i: Topics in Catalysis. - : Springer Science and Business Media LLC. - 1572-9028 .- 1022-5528. ; 56:1-8, s. 201-204
- Relaterad länk:
-
http://dx.doi.org/10...
-
visa fler...
-
https://doi.org/10.1...
-
https://research.cha...
-
visa färre...
Abstract
Ämnesord
Stäng
- The number and type of copper species present in an under-exchanged Cu-Beta zeolite catalyst were characterized using temperature-programmed reduction mass spectrometry (TPR-MS). Both H-2 consumption and H2O evolution were tracked, yielding additional insights into the nature of Cu species. Prior to the TPR-MS tests, catalyst samples were subjected to various high- temperature aging treatments in the presence of O-2 in He, in order to assist with interrogating and resolving different types of sites. Absence of reducible species in the precursor material was confirmed by subjecting the H-form of the same zeolite to the TPR. Upon aging at temperatures below 700 A degrees C, the TPR pattern showed several distinct peaks of different intensities. Aging at 800 A degrees C led to shifting and broadening of these H-2 consumption peaks, as well as to some reduction of the integral amount of the reducible sites. The 900 A degrees C exposure resulted in a drastic change of the TPR pattern, with several new well-resolved H-2 consumption peaks, indicative of drastic changes in the catalyst structure. The integral amount of H-2 consumed quantitatively matched the amount of Cu species present in the catalyst, assuming the stoichiometry. The combination of experimental findings in this work lends support to a hypothesis that different TPR peaks are indicative of different types of sites rather than of step-wise reduction of copper species.
Ämnesord
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Nyckelord
- SCR
- Beta-zeolite
- Cu-zeolite
- Temperature-programmed reduction
Publikations- och innehållstyp
- art (ämneskategori)
- ref (ämneskategori)
Hitta via bibliotek
Till lärosätets databas