Interactions of Vibrationally Excited Molecules with Solid Surfaces

Interactions of Vibrationally Excited Molecules with Solid Surfaces PDF Author: Paul L. Houston
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Book Description
The interaction of gas-phase molecules with solid surfaces is of importance to heterogeneous catalysis, corrosion, air filtration, pollution control, and chemical deactivation. Our research group has recently obtained some of the first direct measurements of the probability for vibrational deactivation during gas-solid collisions. A pulsed infrared laser is used to excite CO of CO2 vibrationally under conditions where the predominant cause of deactivation is due to the gas-surface collision. The probability of relaxation is then monitored by observing the time-dependent decay of infrared fluorescence from the excited molecules. Results for CO2 (001) show that the deactivation probability is 0.22 for collisions with a stainless steel surface, 0.16 for silver, and 0.20 for nickel.

Interactions of Vibrationally Excited Molecules with Solid Surfaces

Interactions of Vibrationally Excited Molecules with Solid Surfaces PDF Author: Paul L. Houston
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Book Description
The interaction of gas-phase molecules with solid surfaces is of importance to heterogeneous catalysis, corrosion, air filtration, pollution control, and chemical deactivation. Our research group has recently obtained some of the first direct measurements of the probability for vibrational deactivation during gas-solid collisions. A pulsed infrared laser is used to excite CO of CO2 vibrationally under conditions where the predominant cause of deactivation is due to the gas-surface collision. The probability of relaxation is then monitored by observing the time-dependent decay of infrared fluorescence from the excited molecules. Results for CO2 (001) show that the deactivation probability is 0.22 for collisions with a stainless steel surface, 0.16 for silver, and 0.20 for nickel.

Interaction of Atoms and Molecules with Solid Surfaces

Interaction of Atoms and Molecules with Solid Surfaces PDF Author: V. Bortolani
Publisher: Springer Science & Business Media
ISBN: 1468487779
Category : Science
Languages : en
Pages : 693

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Book Description
There is considerable interest, both fundamental and technological, in the way atoms and molecules interact with solid surfaces. Thus the description of heterogeneous catalysis and other surface reactions requires a detailed understand ing of molecule-surface interactions. The primary aim of this volume is to provide fairly broad coverage of atoms and molecules in interaction with a variety of solid surfaces at a level suitable for graduate students and research workers in condensed matter physics, chemical physics, and materials science. The book is intended for experimental workers with interests in basic theory and concepts and had its origins in a Spring College held at the International Centre for Theoretical Physics, Miramare, Trieste. Valuable background reading can be found in the graduate-Ievel introduction to the physics of solid surfaces by ZangwilI(1) and in the earlier works by Garcia Moliner and F1ores(2) and Somorjai.(3) For specifically molecule-surface interac tions, additional background can be found in Rhodin and Ertl(4) and March.(S) V. Bortolani N. H. March M. P. Tosi References 1. A. Zangwill, Physics at Surfaces, Cambridge University Press, Cambridge (1988). 2. F. Garcia-Moliner and F. Flores, Introduction to the Theory of Solid Surfaces, Cambridge University Press, Cambridge (1979). 3. G. A. Somorjai, Chemistry in Two Dimensions: Surfaces, Cornell University Press, Ithaca, New York (1981). 4. T. N. Rhodin and G. Erd, The Nature of the Surface Chemical Bond, North-Holland, Amsterdam (1979). 5. N. H. March, Chemical Bonds outside Metal Surfaces, Plenum Press, New York (1986).

Interaction of Highly Vibrationally Excited Molecules with Clean Metal Surfaces. Final Technical Report

Interaction of Highly Vibrationally Excited Molecules with Clean Metal Surfaces. Final Technical Report PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description
The authors present results from a grant funded under the Department of Energy Office of Basic Energy Sciences. A collaboration between Prof. Alec Wodtke of the Department of Chemistry at UCSB and Daniel J. Auerbach of IBM Almaden Research Labs has allowed new experiments on the dynamics of surface chemical reactivity to be successfully executed. High quality data has been generated which provides an excellent test of theoretical models of surface reactivity, a topic of importance to catalysis. The authors have obtained the first experimental measurements on the influence of reactant velocity on the steric effect in a chemical reaction: the dissociative adsorption of hydrogen on copper. They have also designed and built a molecular beam scattering apparatus for the study of highly vibrationally excited molecules and their interactions with clean and oxidized metal surfaces. With this apparatus they have observed the vibrational energy exchange of highly vibrationally excited NO with an oxidized copper surface. Multi-quantum vibrational relaxation was found ([Delta]v = 1-5). Such remarkably strong and efficient vibrational energy transfer represents a qualitatively new phenomenon and is representative of the exciting new behavior that they had hoped might be observable in this project. Evidence of chemical reactivity of vibrationally excited NO on a clean copper surface was also found.

Interaction of Highly Excited Molecules with Solid Surfaces

Interaction of Highly Excited Molecules with Solid Surfaces PDF Author: Mathieu Schmid
Publisher:
ISBN:
Category :
Languages : en
Pages : 157

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Book Description


Research in Progress

Research in Progress PDF Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 604

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Book Description


Research in Progress

Research in Progress PDF Author: United States. Army Research Office
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 316

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Book Description
Vols. for 1977- consist of two parts: Chemistry, biological sciences, engineering sciences, metallurgy and materials science (issued in the spring); and Physics, electronics, mathematics, geosciences (issued in the fall).

Potential Energy Surfaces and Dynamics Calculations

Potential Energy Surfaces and Dynamics Calculations PDF Author: Donald Truhlar
Publisher: Springer Science & Business Media
ISBN: 1475717350
Category : Science
Languages : en
Pages : 859

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Book Description
The present volume is concerned with two of the central questions of chemical dynamics. What do we know about the energies of interaction of atoms and molecules with each other and with solid surfaces? How can such interaction energies be used to understand and make quantitative predictions about dynamical processes like scattering, energy transfer, and chemical reactions? It is becoming clearly recognized that the computer is leading to rapid progress in answering these questions. The computer allows probing dynamical mechanisms in fine detail and often allows us to answer questions that cannot be addressed with current experimental techniques. As we enter the 1980's, not only are more powerful and faster computers being used, but techniques and methods have been honed to a state where exciting and reliable data are being generated on a variety of systems at an unprecedented pace. The present volume presents a collection of work that illustrates the capabilities and some of the successes of this kind of computer-assisted research. In a 1978 Chemical Society Report, Frey and Walsh pointed out that "it is extremely doubtful if a calculated energy of activation for any unimolecular decomposition can replace an experimental deter mination. " However they also recorded that they "believe[d] that some of the elaborate calculations being performed at present do suggest that we may be approaching a time when a choice between reaction mechanisms will be helped by such [computational] work.

Steric Effects in the Chemisorption of Vibrationally Excited Methane on Nickel

Steric Effects in the Chemisorption of Vibrationally Excited Methane on Nickel PDF Author: Bruce L. Yoder
Publisher: Springer Science & Business Media
ISBN: 3642276784
Category : Science
Languages : en
Pages : 185

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Book Description
Bruce Yoder’s thesis outlines his investigation of the dissociative chemisorption of methane (CH4) on a nickel single crystal. In this work Bruce uses a molecular beam and infrared laser techniques to prepare methane in excited rovibrational states. The excited methane molecules are aligned relative to the target nickel surface. Bruce describes the discovery and exploration of a previously unknown steric effect in the dissociation reaction between a vibrationally excited methane molecule and a nickel crystal. From these studies we see that methane molecules are up to twice as reactive when the vibration is aligned parallel rather than perpendicular to the surface. This discovery will help guide the development of detailed predictive models of methane chemisorption, which in turn may lead to better catalysts for the synthesis of several industrially relevant chemicals, including hydrogen fuel from natural gas.

Physics at Surfaces

Physics at Surfaces PDF Author: Andrew Zangwill
Publisher: Cambridge University Press
ISBN: 1316583260
Category : Science
Languages : en
Pages : 470

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Book Description
Physics at Surfaces is a unique graduate-level introduction to the physics and chemical physics of solid surfaces, and atoms and molecules that interact with solid surfaces. A subject of keen scientific inquiry since the last century, surface physics emerged as an independent discipline only in the late 1960s as a result of the development of ultra-high vacuum technology and high speed digital computers. With these tools, reliable experimental measurements and theoretical calculations could at last be compared. Progress in the last decade has been truly striking. This volume provides a synthesis of the entire field of surface physics from the perspective of a modern condensed matter physicist with a healthy interest in chemical physics. The exposition intertwines experiment and theory whenever possible, although there is little detailed discussion of technique. This much-needed text will be invaluable to graduate students and researchers in condensed matter physics, physical chemistry and materials science working in, or taking graduate courses in, surface science.

Molecule Surface Interactions, Volume 76

Molecule Surface Interactions, Volume 76 PDF Author: K. P. Lawley
Publisher: John Wiley & Sons
ISBN: 0470141867
Category : Science
Languages : en
Pages : 398

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Book Description
This text is the first of a two-volume work on molecule surface interactions addressing topics in chemical physics, surface science, physical chemistry, materials science, and electronics and semiconductor manufacture. As with the other titles in the Advances in Chemical Physics series, the chapters are written by an international group of contributors and cover a wide range of important issues in the field.