Download or read book Catalyzed Hydrogenation of Nitrogen and Ethylene on Metal FE PT Single Crystal Surfaces and Effects of Coadsorption written by Staffan Per Gustav Westerberg and published by . This book was released on 2004 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model Catalysis of Ammonia Synthesis and Iron water Interfaces written by Michael James Ferguson and published by . This book was released on 2005 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Materials and Molecular Research Division Annual Report written by Lawrence Berkeley Laboratory. Materials and Molecular Research Division and published by . This book was released on 1986 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Sensitivity Studies of Ethylene Hydrogenation on Platinum and Rhodium Surfaces written by and published by . This book was released on 1996 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The catalytic hydrogenation of ethylene and hydrogen on the well characterized surfaces of the noble metals platinum and rhodium has been studied for the purposes of determining the relative activity of these two substrates as well as the degree of structure sensitivity. The Pt(111) and the Rh(755) single crystal surfaces, as well as Pt and Rh foils, were employed as substrates to study the effect of surface step structure on reactivity. In addition, vibrational spectroscopy studies were performed for ethylene adsorption on the stepped Rh(755) surface. The catalytic reaction were obtained using a combined ultrahigh vacuum chamber coupled with an atmospheric pressure reaction chamber that functioned as a batch reactor. Samples could be prepared using standard surface science techniques and characterized for surface composition and geometry using Auger Electron Spectroscopy and Low Energy Electron Diffraction. A comparison of the reactivity of Rh(111) with the results from this study on Rh(755) allows a direct determination of the effect of step structure on ethylene hydrogenation activity. Structure sensitivity is expected to exhibit orders of magnitude differences in rate as surface orientation is varied. In this case, no significant differences were found, confirming the structure insensitivity of this reaction over this metal. The turnover frequency of the Rh(111) surface, 5 x 101 s−1, is in relatively good agreement with the turnover frequency of 9 x 101 s−1 measured for the Rh(755) surface. Rate measurements made on the Pt(111) surface and the Pt foil are in excellent agreement, both measuring 3 x 102 s−1. Likewise, it is concluded that no strong structure sensitivity for the platinum surfaces exists. High Resolution Electron Energy Loss Spectroscopy studies of adsorbed ethylene on the Rh(755) surface compare favorably with the ethylidyne spectra obtained on the Rh(111) and Rh(100) surfaces.

Download or read book Hydrogenation of Ethylene Over Platinum Single Crystal Surfaces written by Arthur Leonard Backman and published by . This book was released on 1987 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts Index written by and published by . This book was released on 1983 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Correlating Electronic and Catalytic Properties of Bimetallic Surfaces for Model Hydrogenation Reactions written by Amit Goda and published by ProQuest. This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of bimetallic surfaces leads to a change in the electronic properties of the parent metal surface, which results in changes in chemical reactivity. The activity and selectivity of reactions on transition metal surfaces can be increased by creation of such bimetallic combinations. In this dissertation, the correlation of electronic properties of bimetallic surfaces with the reaction pathways of C 2 hydrocarbons, catalytic properties of higher alkenes and selective reduction of acetic acid to acetaldehyde is illustrated. For the study on C 2 hydrocarbons, Density Functional Theory (DFT) was used to study the binding of hydrogen, ethylene, acetylene, ethyl and vinyl on monometallic and bimetallic transition metal surfaces. The binding energies (B.E.) of these species were found to correlate with the d-band centers of the surfaces. DFT-calculated B.E. and BOC-calculated activation barrier values were used to calculate the selectivity for acetylene hydrogenation vs. ethylene hydrogenation. The results showed that for monometallic fcc(111) surfaces, the selectivity for acetylene hydrogenation followed the trend Ni> Pt> Pd. In addition, the general trend in the binding energy of other alkenes, including butene, pentane, hexene, and cyclohexene also followed similar binding energy trend as compared to ethylene. Adsorption studies were also carried out for benzene in two favorable configurations. Along with the adsorption trends, DFT based studies were carried out to study the effect of hydrocarbon chain length and cyclization on the adsorption on Pt-based bimetallic surfaces. In the case of selective reduction of acetic acid, DFT calculations were used to study the modes and energies of adsorption of the involved intermediates along with the overall reaction energies for the elementary steps. DFT calculations on acetic acid, acetaldehyde and ethanol showed that the binding energy (B.E.) of the molecules decreases as the surface d-band center shifts away from the Fermi level. It was observed that ethanol binds more strongly than acetaldehyde on Pt(111) as well as the subsurface Ni on Pt (Pt-Ni-Pt) surface, but the trend reverses when Ni is on top of Pt (Ni-Pt-Pt). This change in B.E. affects the overall heat of reaction for ethoxy going to ethanol, making it highly exothermic on Pt(111) and Pt-Ni-Pt surfaces, while it is endothermic on the Ni-Pt- Pt surface. These changes in the thermodynamics of reactions should affect the rate determining steps toward selective acetaldehyde formation, which was determined by calculating the activation barriers for the elementary steps.

Download or read book Flash Desorption of Hydrogen and Ethylene and Equilibration of Hydrogen and Deuterium on Platinum Single Crystal Surfaces written by Kun-Er C. Lu and published by . This book was released on 1974 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Addressing Key Unanswered Questions Regarding the Mechanism of Ethylene Hydrogenation on Pt Single Crystals written by Juan Pablo Simonovis and published by . This book was released on 2015 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its first proposal by Horiuti and Polanyi, the mechanism of the catalytic hydrogenation of ethylene over Pt has been the subject of much debate, and there are some pending questions still regarding the transformations that take place on the surface of the working catalysts. Model studies on ideal transition metal surfaces under ultra-high vacuum (UHV) conditions have allotted very useful information regarding the possible pathways for this reaction. However, past findings from studies with model systems do not always correlate with results obtained under more realistic catalytic conditions.

Download or read book Microcalorimetric Measurements of Differential Heats of Adsorption on Reactive Metal Surfaces written by Brian Edward Spiewak and published by . This book was released on 1997 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Chemical Society written by and published by . This book was released on 1987 with total page 1236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Surface Science and Catalytic Studies of Hydrocarbon Reactions Over Platinum Single Crystal Surfaces written by Francisco Zaera and published by . This book was released on 1984 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Sensitivity Studies of Ethylene Hydrogenation on Platinum and Rhodium Surfaces written by Michael Andrew Quinlan and published by . This book was released on 1996 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2566 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1986 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: