283 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Reaction Intermediates"  
prev Results: 121 - 144 next
open access

Fundamental studies of catalytic processing of synthetic liquids. Quarterly progress report, October 1, 1991--December 31, 1991

Description: This project revolves around understanding the fundamental processes involved in the catalytic removal of harmful oxygenated organics present in coal liquids. We are modelling the complex type of sulfided Mo catalyst proposed for these reactions with simple single crystal surfaces. These display a controlled range and number of reaction sites and can be extensively characterized by surface science techniques. We then investigate the reaction pathways for representative simple oxygenates upon th… more
Date: January 22, 1992
Creator: Watson, P. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Bench scale demonstration and conceptual engineering for DETOX{sup SM} catalyzed wet oxidation

Description: Laboratory and bench scale studies of the DETOX{sup SM} catalyzed wet oxidation process have been performed with the object of developing the process for treatment of hazardous and mixed wastes. Reaction orders, apparent rates, and activation energies have been determined for a range of organic waste surrogates. Reaction intermediates and products have been analyzed. Metals` fates have been determined. Bench scale units have been designed, fabricated, and tested with solid and liquid organic wa… more
Date: June 1, 1994
Creator: Moslander, J.; Bell, R.; Robertson, D.; Dhooge, P. & Goldblatt, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Catalytic conversion of light alkanes. Quarterly progress report, April 1--June 30, 1992

Description: The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past qu… more
Date: June 30, 1992
Creator: Lyons, J. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The thermodynamic properties of 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene

Description: Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for both materials based on the measurement results. Entropies, enthalpies, and… more
Date: December 1, 1992
Creator: Chirico, R. D.; Knipmeyer, S. E.; Nguyen, A.; Smith, N. K. & Steele, W. V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Ligand intermediates in metal-catalyzed reactions. Annual technical report, September 1, 1990--August 31, 1991

Description: This report consists of six sections, which cover pi/sigma equilibria in aldehyde and ketone complexes, abstraction of vinylic protons from alkene complexes, mechanism of rearrangement of alkylidene to alkene complexes, rearrangement of terminal acetylene to vinylidene complexes, synthesis and reactivity of lithiocarbide complexes, and new catalysts for the epimerization of secondary alcohols; carbon-hydrogen bond activation in alkoxide complexes. (WET)
Date: September 6, 1991
Creator: Gladysz, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Chemical Additives on the Synthesis of Ethanol. Technical Progress Report No. 4, June 16, 1988--September 15, 1988

Description: The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experime… more
Date: November 14, 1988
Creator: Chuang, S. S. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Moist air reaction with excess UF{sub 6}

Description: The moist air reaction with uranium hexafluoride (UF{sub 6}) has been studied at conditions simulating UF{sub 6} hydrolysis during air inleakage in the cascade. In excess UF{sub 6}, the reaction mechanism is more complicated than predicted by the simple gas-phase reaction of one UF{sub 6} molecule with two water molecules to form uranyl fluoride and hydrogen fluoride. The initial UF{sub 6} consumption is significantly greater than predicted, suggesting that a metastable uranium compound is form… more
Date: August 1, 1989
Creator: Reiner, R. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 April--30 June 30 1996

Description: A series of CuMgCeO{sub x} catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. Kinetic studies of methanol and ethanol coupling reactions on K-Cu/MgO/CeO{sub 2} and MgO/CeO{sub 2} catalysts indicate that Cu enhances the rates of alcohol dehydrogenation. The cross-coupling reactions of acetaldehyde and {sup 13}C-labeled methanol produce singly-labeled propionaldehyde, suggesting that it forms by th… more
Date: July 25, 1996
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Improving electronic structure methods to predict nano-optoelectronics and nano-catalyst functions.

Description: This report focuses on quantum chemistry and ab initio molecular dynamics (AIMD) calculations applied to elucidate the mechanism of the multi-step, 2-electron, electrochemical reduction of the green house gas molecule carbon dioxide (CO{sub 2}) to carbon monoxide (CO) in aqueous media. When combined with H{sub 2} gas to form synthesis ('syn') gas, CO becomes a key precursor to methane, methanol, and other useful hydrocarbon products. To elucidate the mechanism of this reaction, we apply computa… more
Date: October 1, 2009
Creator: Nielsen, Ida Marie B.; Marzari, Nicola; Shelnutt, John Allen; Kulik, Heather J.; Medforth, Craig John & Leung, Kevin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Probe molecule studies: Active species in alcohol synthesis. Quarterly report No. 6, January 1992--March 1992

Description: The goal of this research is to develop a better understanding of the mechanisms of formation of alcohols and other oxygenates from syngas over supported catalysts. Probe molecules will be added in situ during the reaction to help delineate reaction pathways and identify reaction intermediate species. The key of our study is to investigate how the species generated by these probe molecules interact with surface species present during oxygenate formation.
Date: April 1, 1992
Creator: Blackmond, D. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Semiconductor electrochemistry of coal pyrite. Technical progress report, October--December 1992

Description: This project seeks to advance the fundamental understanding of the physics-chemical processes occurring at the pyrite/aqueous interface, in the context of coal cleaning, coal desulfurization, and acid minedrainage. A novel approach to the study of pyrite aqueous electrochemistry is proposed, based on the use of both synthetic and natural ( i.e. coal-derived) pyrite specimens, the utilization of.pyrite both in the form of micro (i.e. colloidal and subcolloidal) and macro (i.e. rotating ring disk… more
Date: February 1, 1993
Creator: Osseo-Asare, K. & Wei, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fundamental studies of the mechanism of catalytic reactions with catalysts effective in the gasification of carbon solids and the oxidative coupling of methane. Quarterly report, July 1--September 30, 1992

Description: Work will continue on the oxidative coupling reaction of methane over ternary oxide catalysts to produce C{sub 2}, C{sub 3} and C{sub 4} hydrocarbons and Particularly Olefins with high selectivity. The work which has shown that close to 100% selectivity can be obtained has received wide attention and has resulted in collaborative efforts with industry (CRADA) towards the development of a commercial process. An immediate purpose of additional work is to increase the conversion without diminishin… more
Date: September 1, 1992
Creator: Heinemann, H.; Somorjai, G. A. & Perry, D. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The single electron chemistry of coals, July 1, 1991--September 30, 1991

Description: The objectives of this work are to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. (1) Attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine. (2) The molecule, N, N-diphenyl-phenylendiamine, will be deposited in coals to characterize their native free radicals. (3) Tetracyanoquinodimetha… more
Date: December 31, 1991
Creator: Larsen, John W. & Eskay, T. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Early events in radiation chemistry and in photoionization

Description: Real-time studies of aliphatic and aromatic hydrocarbons by pulse radiolysis and laser photoionization reveal the chemistry of the ionic species in the condensed phase. The occurrence of radical cation reactions with solvent molecules provides the core mechanism capable of explaining a wide range of observations in photoionization and radiation chemistry. The study of products and transients in photoionization of aromatic solutes in hydrocarbon and alcohol solvent illustrates several details of… more
Date: December 31, 1992
Creator: Trifunac, A. D.; Loffredo, D. M. & Liu, A.-D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Semiconductor electrochemistry of coal pyrite. Technical progress report, July--September 1992

Description: The kinetics of the formation of Fe(HS){sup 2}-n{sub n,} the intermediate in the formation of FeS (from the reaction between aqueous sulfide ions and dissolved FE(II) salts) was studied with a stopped-flow spectrophotometric technique. As described in the previous report, the absorbance-time curve indicated that a black substance formed within the first few seconds of the reaction; this material subsequently decomposed gradually to give a lighter dark product within the following several minute… more
Date: December 31, 1992
Creator: Osseo-Asare, K. & Wei, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Aromatics oxidation and soot formation in flames. Progress report, August 15, 1990--August 14, 1993

Description: This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify, and to conf… more
Date: April 1, 1993
Creator: Howard, J. B.; Pope, C. J.; Shandross, R. A. & Yadav, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Study of Intermediates From Transition Metal Excited-State Electron-Transfer Reactions. [Annual] Progress Report, August 1, 1989--July 31, 1992

Description: Conventional and fast-kinetics techniques of photochemistry, photophysics, radiation chemistry, and electrochemistry were used to study the intermediates involved in transition metal excited-state electron-transfer reactions. These intermediates were excited state of Ru(II) and Cr(III) photosensitizers, their reduced forms, and species formed in reactions of redox quenchers and electron-transfer agents. Of particular concern was the back electron-transfer reaction between the geminate pair form… more
Date: July 31, 1992
Creator: Hoffman, M. Z.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Chemical Additives on the Synthesis of Ethanol. Technical Progress Report 17, September 16, 1991--December 15, 1991

Description: The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effects of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experim… more
Date: December 20, 1991
Creator: Chuang, S. S. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads. Technical progress report

Description: This research project involves the design, synthesis and study of molecules which mimic many of the important aspects of photosynthetic electron and energy transfer. The knowledge gained from the study of synthetic model systems which abstract features of the natural photosynthetic apparatus can be used to design artificial photosynthetic systems which employ the basic physics and chemistry of photosynthesis to help meet mankind`s energy needs. More specifically, the proposed models are designe… more
Date: April 12, 1988
Creator: Gust, J. D. Jr. & Moore, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Chemical Additives on the Synthesis of Ethanol. Technical Progress Report No. 10, December 16, 1989--March 15, 1990

Description: The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experime… more
Date: July 1, 1990
Creator: Chuang, S. S. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Chemical Additives on the Synthesis of Ethanol. Technical Progress Report No. 9, September 16, 1989--December 15, 1989

Description: The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experime… more
Date: April 9, 1990
Creator: Chuang, S. S. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Sulfided heterogeneous, bimetallic RuMo catalysts derived from mixtures of Ru{sub 3}(CO){sub 12} (or RuCl{sub 3}) and a molybdenum heteropolyanion. The reactions of ethanol with tetrahydroquinoline

Description: Efforts have been made to develop Ru/Mo bimetallic catalyst systems for hydrodenitrogenation (HDN) of tetrahydroquinoline (THQ)- In the course of these studies, it was discovered that in ethanol, under H{sub 2} and in the presence Of CS2, Precatalyst solutions containing Ru [as Ru{sub 3} (CO){sub 12} or RuCl{sub 3}] and Mo [as the H{sub 3}PMO{sub 12}0{sub 40} heteropolyanion (HPA)] decompose to form bimetallic, sulfided particles. Particle diameters run from 0.1 to 5 {mu}m depending on the rate… more
Date: September 1, 1992
Creator: Koo, Sang-Man; Ryan, D. & Laine, R. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fundamental studies of reactive intermediates in homogeneous catalysis

Description: The studies involve dissociation of Fe(CO){sub n}{sup {minus}}, Ni(CO){sub n}{sub {minus}}, and other carbonyl anions; decarboxylation of (CO){sub 4}FeCOOH{sup {minus}} to form CO{sub 2} and (CO){sub 4}FeH{sup {minus}} in the water gas shift reaction; gas-phase bimolecular reactions of carbonyl anions and O{sub 2}; reaction of O{sub 2} with CpMn(CO){sub 2}{sup {minus}}; gas-phase chemistry of fullerene anions; and gas-phase thermochemistry of bicarbonate ion, bisulfite ion, and their conjugate … more
Date: October 1, 1993
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen