Author: Robert Brian Bailey
Publisher:
ISBN:
Category :
Languages : en
Pages : 276
Book Description
Infrared Absorption Spectroscopy of Carbon Monoxide on Nickel Films
Infrared Absorption Spectroscopy of Carbon Monoxide on Nickel Films
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Sensitive vibrational spectra of carbon monoxide molecules adsorbed on evaporated nickel films have been measured by attaching a thermometer to the sample, cooling the assembly to liquid helium temperatures, and recording the temperature changes which occur when infrared radiation is absorbed. The measurements are made in an ultrahigh vacuum chamber in which the sample surface can be cleaned, heated, exposed to gas molecules and cooled to 1.6 K for the infrared measurements. The spectra of chemisorbed CO molecules are interpreted in terms of the linear and bridge adsorption sites on the nickel surface, and they show how the distribution of molecules among these sites changes when the CO coverage increases and intermolecular forces become important. The spectra of physically adsorbed molecules in both monolayer and multilayer films are also reported. Absorptions as small as five parts in 105 of the incident radiation can presently be detected in spectra covering broad bands of infrared frequencies with a resolution of 2 cm−1. This high sensitivity is attributable to the low noise and reduced background signal of the thermal detection scheme, to the stability of the rapid scan Fourier transform infrared spectrometer, and to the automated computerized data acquisition electronics. Better performance is expected in future experiments on single crystal samples as well as evaporated films. This will make it possible to study molecules with weaker absorptions than CO and to look for evidence of chemical reactions between different adsorbed molecules.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Sensitive vibrational spectra of carbon monoxide molecules adsorbed on evaporated nickel films have been measured by attaching a thermometer to the sample, cooling the assembly to liquid helium temperatures, and recording the temperature changes which occur when infrared radiation is absorbed. The measurements are made in an ultrahigh vacuum chamber in which the sample surface can be cleaned, heated, exposed to gas molecules and cooled to 1.6 K for the infrared measurements. The spectra of chemisorbed CO molecules are interpreted in terms of the linear and bridge adsorption sites on the nickel surface, and they show how the distribution of molecules among these sites changes when the CO coverage increases and intermolecular forces become important. The spectra of physically adsorbed molecules in both monolayer and multilayer films are also reported. Absorptions as small as five parts in 105 of the incident radiation can presently be detected in spectra covering broad bands of infrared frequencies with a resolution of 2 cm−1. This high sensitivity is attributable to the low noise and reduced background signal of the thermal detection scheme, to the stability of the rapid scan Fourier transform infrared spectrometer, and to the automated computerized data acquisition electronics. Better performance is expected in future experiments on single crystal samples as well as evaporated films. This will make it possible to study molecules with weaker absorptions than CO and to look for evidence of chemical reactions between different adsorbed molecules.
Infrared Emission Spectroscopy of Carbon Monoxide on Nickel
Author: Shirley Chiang
Publisher:
ISBN:
Category :
Languages : en
Pages : 306
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 306
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1134
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1134
Book Description
Vibrational Spectroscopy of Molecules on Surfaces
Author: Theodore E. Madey
Publisher: Springer Science & Business Media
ISBN: 1468487590
Category : Science
Languages : en
Pages : 478
Book Description
The observation of the vibrational spectra of adsorbed species provides one of the most incisive methods for und erst an ding chemical and physical phenomena on surfaces. At the present time, many approaches may be applied to studies of molecular vibrations on surfaces. Some of these are used on high-area solids of technological importance (e.g., heterogeneous catalysts) while others are applied to single-crystal substrates to gain better understanding under conditions of controlled surface structure. This book has attempted to bring together in one place a discussion of the major methods used to measure vibrational spectra of surface species. The emphasis is on basic concepts and experimental methods rather than a current survey of the extensive literature in this field. Two introductory chapters describe the basic theoretical aspects of vibrational spectroscopy on surfaces, dealing with normal modes and excitation mechanisms in vibrational spectroscopy. The remaining seven chapters deal with various methods employed to observe surface vibra tions. These are arranged in an order that first treats the use of various methods on surfaces that are not of the single-crystal type. It is in this area that the field first got started in the late 1940s with pioneering work by Terenin and others in the Soviet Union, and by Eisehens and others in the United States in the 1950s. The last four chapters deal with relatively recent methods that permit vibrational studies to be made on single crystal substrates.
Publisher: Springer Science & Business Media
ISBN: 1468487590
Category : Science
Languages : en
Pages : 478
Book Description
The observation of the vibrational spectra of adsorbed species provides one of the most incisive methods for und erst an ding chemical and physical phenomena on surfaces. At the present time, many approaches may be applied to studies of molecular vibrations on surfaces. Some of these are used on high-area solids of technological importance (e.g., heterogeneous catalysts) while others are applied to single-crystal substrates to gain better understanding under conditions of controlled surface structure. This book has attempted to bring together in one place a discussion of the major methods used to measure vibrational spectra of surface species. The emphasis is on basic concepts and experimental methods rather than a current survey of the extensive literature in this field. Two introductory chapters describe the basic theoretical aspects of vibrational spectroscopy on surfaces, dealing with normal modes and excitation mechanisms in vibrational spectroscopy. The remaining seven chapters deal with various methods employed to observe surface vibra tions. These are arranged in an order that first treats the use of various methods on surfaces that are not of the single-crystal type. It is in this area that the field first got started in the late 1940s with pioneering work by Terenin and others in the Soviet Union, and by Eisehens and others in the United States in the 1950s. The last four chapters deal with relatively recent methods that permit vibrational studies to be made on single crystal substrates.
The Infrared Absorption Spectrum of Carbon Monoxide
Author: Erwin Foster Lowry
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 24
Book Description
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 24
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 632
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 632
Book Description
Using Infrared Spectroscopy to Determine the Arrangement of Carbon Monoxide Adsorbed on Nickel, Palladium and Platinum
Author: Robert Kurtis Brandt
Publisher:
ISBN:
Category : Adsorption
Languages : en
Pages : 762
Book Description
Publisher:
ISBN:
Category : Adsorption
Languages : en
Pages : 762
Book Description
Air Pollution Abstracts
Author:
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 588
Book Description
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 588
Book Description
Journal of the American Chemical Society
Author: American Chemical Society
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 1544
Book Description
Proceedings of the Society are included in v. 1-59, 1879-1937.
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 1544
Book Description
Proceedings of the Society are included in v. 1-59, 1879-1937.