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You searched for subject:(ruthenium co catalyst). Showing records 1 – 3 of 3 total matches.

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North Carolina State University

1. Arrowood, Benjamin Nathan. Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins.

Degree: MS, Chemistry, 2003, North Carolina State University

A ruthenium(II) complex TpRu(CO)(CH3)(NCCH3) (Tp = hydridotris(pyrazolyl)borate) was prepared from TpRu(CO)2(CH3) by refluxing in acetonitrile with (CH3)3NO. Heating a solution of TpRu(CO)(CH3)(NCCH3) in CDCl3 to 50 °C with various equivalents of CD3CN indicates that the Ru-NCCH3 undergoes exchange with CD3CN and is independent of CD3CN concentration. Reactions with styrene or methyl methacrylate in the presence of catalytic quantities of TpRu(CO)(CH3)(NCCH3) at 90 °C result in the production of polystyrene and polymethyl methacrylate, respectively. An inverse dependence of polystyrene molecular weight on concentration of added cumene indicates that a radical polymerization mechanism is likely. In addition, the polymerization of styrene or methyl methacrylate occurs in the presence of carbon tetrachloride or methyl dichloroacetate with catalytic quantities of TpRu(CO)(CH3)(NCCH3) at 90°. In both cases, polymer conversion rates are sluggish and molecular weight distributions are broad. The slow reaction rates are attributed to a high Ru(III/II) redox couple that favors Ru(II). Reactions with TpRu(CO)(CH3)(NCCH3) in benzene charged with ethylene at 90 °C do not produce polyethylene. Rather, catalytic synthesis of ethylbenzene as well as 1,3- and 1,4-diethylbenzene is observed. Advisors/Committee Members: T. Brent Gunnoe, Committee Chair (advisor), James D. Martin, Committee Member (advisor), Christopher B. Gorman, Committee Member (advisor).

Subjects/Keywords: controlled radical polymerization; atom transfer radical polymerization; ruthenium catalyst; polymerization of olefins; TpRu(CO)(CH3)(NCCH3)

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APA (6th Edition):

Arrowood, B. N. (2003). Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins. (Thesis). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/2928

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Arrowood, Benjamin Nathan. “Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins.” 2003. Thesis, North Carolina State University. Accessed November 14, 2019. http://www.lib.ncsu.edu/resolver/1840.16/2928.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Arrowood, Benjamin Nathan. “Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins.” 2003. Web. 14 Nov 2019.

Vancouver:

Arrowood BN. Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins. [Internet] [Thesis]. North Carolina State University; 2003. [cited 2019 Nov 14]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2928.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Arrowood BN. Preparation and characterization of a ruthenium(II) catalyst for radical polymerization of olefins. [Thesis]. North Carolina State University; 2003. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2928

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of Notre Dame

2. Hangyao Wang. Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>.

Degree: PhD, Chemical Engineering, 2009, University of Notre Dame

Base metal oxides have long been of interest as catalysts for oxidation of small molecules such as CO and NO. As an example, Ru metal becomes active for catalytic oxidation only after partial surface oxidation. The (110) surface of RuO2 is a convenient model for the oxidized metal surface because it is active for CO oxidation and well characterized. In this study we employ plane-wave, supercell DFT calculations to examine the mechanisms of oxygen activation, COO oxidation as well as surface poisoning on RuO2(110) surface. We first consider O2 adsorption and dissociation, and show that the molecular O2 species observed in TPD experiments and identified as a precursor to O2 dissociation is in fact a spectator present only at high coverages of surface O. We then study the CO and NO oxidation mechanisms on the RuO2(110) surface and compare the fundamental differences that lead to complete different catalytic reactivity of this surface on CO and NO oxidations. Practical applications of oxidation catalysts are limited by surface poisoning, so it is important to understand and ultimately to learn to bypass surface poisoning. We investigate catalytic CO oxidation and its competition with surface poisoning by employing first-principles thermodynamics as well as micro-kinetic modeling method. We identify both carbonate and bicarbonate surface poisons and show that the coverage of the latter is highly sensitive to water concentration and likely accounts for the surface poisoning observed experimentally. As an attempt to understand how surface metal oxides develop on metal surfaces and what their exact role is during oxidation, we study the formation of oxide nuclei on Pt surface. We hypothesize that the roughening on Pt surfaces observed in STM experiments initiates from small surface PtxOy clusters. We quantify the stability of these clusters vs. the cluster size and oxygen chemical potential and explore whether these clusters might account for the anomalously high catalytic activity of Pt and other metals at high oxygen pressure. Advisors/Committee Members: S. Alex Kandel, Committee Member, Masaru Kuno, Committee Chair, William F. Schneider, Committee Member, Edward Maginn, Committee Member, Paul McGinn, Committee Member.

Subjects/Keywords: oxygen activation; first principles simulation; ruthenium dioxide; surface poisoning; transition state theory; micro-kinetic modeling; activation energy; catalyst deactivation; reaction mechanism; heterogeneous catalysis; reaction energy; NO oxidation; phase diagram; CO oxidation; density functional theory; catalytic oxidation; adsorption

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wang, H. (2009). Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>. (Doctoral Dissertation). University of Notre Dame. Retrieved from https://curate.nd.edu/show/j9601z42v4d

Chicago Manual of Style (16th Edition):

Wang, Hangyao. “Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>.” 2009. Doctoral Dissertation, University of Notre Dame. Accessed November 14, 2019. https://curate.nd.edu/show/j9601z42v4d.

MLA Handbook (7th Edition):

Wang, Hangyao. “Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>.” 2009. Web. 14 Nov 2019.

Vancouver:

Wang H. Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>. [Internet] [Doctoral dissertation]. University of Notre Dame; 2009. [cited 2019 Nov 14]. Available from: https://curate.nd.edu/show/j9601z42v4d.

Council of Science Editors:

Wang H. Atomistic Studies of Oxidation Catalysis and Surface Poisoning on Transition Metal Oxide Surfaces</h1>. [Doctoral Dissertation]. University of Notre Dame; 2009. Available from: https://curate.nd.edu/show/j9601z42v4d

3. Behnia, Izad. Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2.

Degree: 2013, University of Western Ontario

The present study targets to convert aqueous fraction of fast pyrolysis oil into methane and hydrogen gases via supercritical water gasification (SCWG). Water above its critical point is referred to as supercritical water, which has unique properties such as a loss of hydrogen bonding, becoming an excellent solvent for organic compounds. In this thesis, SCWG was used to gasify slurry materials into high calorific gases including CH4 and H2. Production selectivity towards more methane or hydrogen was affectively controlled by operational conditions. However, in the absence of catalyst (bank test), gas formation was very minimal. SCWG of glucose as an organic model compound was studied to screen the best catalyst for methane production. Ni20%Ru2%/γ-Al2O3 catalyst was able to convert all carbon in glucose to gases at a temperature of as low as 500 °C and weight-hourly space velocity (WHSV) of 3 h-1. This catalyst significantly promoted methane production and produced 0.5 mol methane per mole of carbon in the glucose feedstock. High stability and activity of this catalyst were observed during 20 hours on stream. It was also found out from this study that nickel loading, temperature, substrate concentration and feeding rate or WHSV greatly affected carbon conversion and yields of CH4 and H2 in SCWG. For instance, higher temperatures favor hydrogen formation while lower temperatures promote methane yield. Moreover, the Ni20%Ru2%/γ-Al2O3 catalyst demonstrated to be active for gasifying the aqueous fraction of fast pyrolysis oil via SCWG. Besides, the aqueous fraction of pyrolysis oil was gasified to a high extent in the presence of this catalyst, and 0.9 mol/mol of carbon in feedstock (2.98 wt.% C) was converted into CH4 and CO2 at 700 °C.

Subjects/Keywords: supercritical water gasification (SCWG); glucose; aqueous fraction of pyrolysis oil; catalyst screening; nickel catalyst; nickel loading; ruthenium co-catalyst; effects of temperature; effects of WHSV; effects of substrate concentration.; Catalysis and Reaction Engineering; Environmental Engineering

Ruthenium has also been used as a co-catalyst to promote the performance of Ni catalyst by… …reduced nickel catalyst favored the water-gas shift reaction, and ruthenium suppressed tar and… …69 4.2.1. Feedstock and Catalyst preparation… …78 4.3.4. Catalyst Characterization… …catalyst at 400 C (Elliott et al., 1988)… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Behnia, I. (2013). Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2. (Thesis). University of Western Ontario. Retrieved from https://ir.lib.uwo.ca/etd/1567

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Behnia, Izad. “Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2.” 2013. Thesis, University of Western Ontario. Accessed November 14, 2019. https://ir.lib.uwo.ca/etd/1567.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Behnia, Izad. “Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2.” 2013. Web. 14 Nov 2019.

Vancouver:

Behnia I. Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2. [Internet] [Thesis]. University of Western Ontario; 2013. [cited 2019 Nov 14]. Available from: https://ir.lib.uwo.ca/etd/1567.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Behnia I. Treatment of Aqueous Biomass and Waste via Supercritical Water Gasification for the Production of CH4 and H2. [Thesis]. University of Western Ontario; 2013. Available from: https://ir.lib.uwo.ca/etd/1567

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.