Author: Susan Eileen Shore
Publisher:
ISBN:
Category :
Languages : en
Pages : 170
Book Description
Nuclear Magnetic Resonance Study of the Bonding of Carbon Monoxide to Palladium and Platinum Surfaces
Author: Susan Eileen Shore
Publisher:
ISBN:
Category :
Languages : en
Pages : 170
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 170
Book Description
An NMR Study of Diffusion of Carbon Monoxide on Metal Surfaces
Author: Lino Renan Becerra Rusconi
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The author reports the study of diffusion of carbon monoxide on supported palladium and platinum clusters by Nuclear Magnetic Resonance. As part of these studies, a novel NMR technique for studying diffusion (called an S-shape sequence) has been implemented. He finds that the CO adlayer on Pd may be present in one of two phases, a low and a high temperature phase. The transition temperature from one phase to the other depends on cluster size and has been expressed by a phase diagram. In the low temperature phase CO is bridge bonded to large clusters though on small clusters the bonding appears to be linear. In this phase, the packing of the CO adlayer on large clusters is equivalent to the one of CO on Pd (111) surfaces whereas on small clusters the packing is less dense. The CO diffusion rate in this phase has been measured by the S-shape method. For the high temperature phase CO is much more mobile than for the low temperature phase as is evidenced by motional narrowing of the NMR line. At a given temperature, the diffusion rate in this phase is faster on larger clusters. Using the S-shape method to study diffusion of CO on Pt, the author has found that the barrier for diffusion is larger for small clusters (11 kcal/mol) than for large ones (6 kcal/mol). The value for the large clusters agrees with results in the literature for single crystal surfaces. Reducing the CO coverage increases the diffusion rate, as would be the case if diffusion went by a CO vacancy mechanism. These experiments suggest that below the motional narrowing regime the CO molecules that are bridge bonded are diffusing while the linearly bonded remain fixed. Thus there are two interpenetrating lattices, one of mobile CO's the other of fixed CO's.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The author reports the study of diffusion of carbon monoxide on supported palladium and platinum clusters by Nuclear Magnetic Resonance. As part of these studies, a novel NMR technique for studying diffusion (called an S-shape sequence) has been implemented. He finds that the CO adlayer on Pd may be present in one of two phases, a low and a high temperature phase. The transition temperature from one phase to the other depends on cluster size and has been expressed by a phase diagram. In the low temperature phase CO is bridge bonded to large clusters though on small clusters the bonding appears to be linear. In this phase, the packing of the CO adlayer on large clusters is equivalent to the one of CO on Pd (111) surfaces whereas on small clusters the packing is less dense. The CO diffusion rate in this phase has been measured by the S-shape method. For the high temperature phase CO is much more mobile than for the low temperature phase as is evidenced by motional narrowing of the NMR line. At a given temperature, the diffusion rate in this phase is faster on larger clusters. Using the S-shape method to study diffusion of CO on Pt, the author has found that the barrier for diffusion is larger for small clusters (11 kcal/mol) than for large ones (6 kcal/mol). The value for the large clusters agrees with results in the literature for single crystal surfaces. Reducing the CO coverage increases the diffusion rate, as would be the case if diffusion went by a CO vacancy mechanism. These experiments suggest that below the motional narrowing regime the CO molecules that are bridge bonded are diffusing while the linearly bonded remain fixed. Thus there are two interpenetrating lattices, one of mobile CO's the other of fixed CO's.
Nuclear Magnetic Resonance Study of Carbon Monoxide Bonded to Platinum Catalysts Via the Study of 1̳3̳C T1̳'s
Author: Eric Joseph Dean
Publisher:
ISBN:
Category :
Languages : en
Pages : 406
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 406
Book Description
Carbon-13 - Nuclear - Magnetic - Resonance of Carbon Monoxide on Platinum: Study of a Highly Dispersed Catalyst (Nmr).
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
13c-nuclear-magnetic-resonance of Carbon Monoxide on Platinum, Study of a Highly Dispersed Catalyst
Author: Serge Laurent Rudaz
Publisher:
ISBN:
Category :
Languages : en
Pages : 394
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 394
Book Description
A New Approach to the Study of Surface Phenomena: Measurements of Diffusion Rates, Intermolecular Distances and Electronic Properties of Carbon Monoxide Chemisorbed on Supported Platinum Catalysts by Nuclear Magnetic Resonance
Author:
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ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Energy Research Abstracts
Author:
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ISBN:
Category : Power resources
Languages : en
Pages : 780
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 780
Book Description
Comprehensive Dissertation Index
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1016
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1016
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1370
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1370
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
The Effect of Additives on the Reactivity of Palladium Surfaces for the Chemisorption and Hydrogenation of Carbon Monoxide
Author: Thomas George Rucker
Publisher:
ISBN:
Category :
Languages : en
Pages : 404
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 404
Book Description