Density functional theory investigation of the reaction mechanisms for selective oxidation of alcohols on gold catalysts

Download

index.pdf

Date

2016

Author

Dernek, Ozan

Metadata

Show full item record

Item Usage Stats

118
views

37
downloads

Most alcohols, when exposed to oxygen, are converted into CO2 and H2O as a result of a combustion reaction. Such reactions consist of several intermediate steps, which produce industrially valuable chemical species such as esters, ketones, carboxylic acids and aldehydes. These chemicals find uses in a wide range of applications in food, pharmaceutical, polymer and plating industries along with many others. As a result, there are considerable economical interests in the design of efficient, low-cost and environmentally low-impact synthetic routes of these products. Selective oxidation provides a way to interrupt the combustion reaction at the desired stage and extract the by-product of interest. The variety of these intermediate products and the particular mechanism is dictated by the environment and the catalyst used. Experimental studies have already indicated that the Au nanoparticles and Au surfaces pre-treated with atomic oxygen successfully catalyze selective oxidation. Current oxygen pretreatment techniques are, however, difficult and costly. The aim of this study is to design Au surfaces by means of doping the surface with Ni and Rh atoms in low concentrations to increase the performance of the surface for selective oxidation of ethanol. We utilize arguably the most successful theoretical method to ever have been used in surface science, namely Density Functional Theory (DFT), to understand the selective oxidation of ethanol. We present results concerning the dissociation of ethanol into subcomponents on these doped surfaces.

Subject Keywords

Density functionals., Surfaces (Physics)., Alcohols., Oxidation., Catalysts., Gold.

URI

http://etd.lib.metu.edu.tr/upload/12620409/index.pdf
https://hdl.handle.net/11511/26082

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Density functional and dynamics study of the dissociative adsorption of hydrogen on Mg (0001) surface Kecik, D.; Aydınol, Mehmet Kadri (Elsevier BV, 2009-01-15) A first principles study is performed to investigate the adsorption characteristics of hydrogen on magnesium surface. Substitutional and on-surface adsorption energies are calculated for Mg (0001) surface alloyed with the selected elements. To further analyze the hydrogen-magnesium interaction, first principles molecular dynamics method is used which simulates the behavior of H-2 at the surface. Also, charge density differences of substitutionally doped surface configurations were illustrated. Accordingly, ...
Experimental investigation of carbon dioxide injection effects on methane-propane-carbon dioxide mixture hydrates Abbasov, Abbas; Merey, Sukru; Parlaktuna, Mahmut (2016-08-01) In this research, first, hydrate with high saturation in porous media (sand sediments) was formed in fully filled high pressure cell by using a mixture of the following gases at 4 degrees C: methane (CH4), propane (C3H8) and carbon dioxide (CO2). The feed mole percent of the gases used was selected as follows: CH4 (95%), C3H8 (3%), CO2 (2%). This selection was made in order to form natural gas hydrate of thermogenic origin (sII type hydrate). Thereafter, CO2 injection into the high saturation hydrate media ...
Influence of oxygen concentration on the sooting behavior of ethanol droplet flames in microgravity conditions Yozgatlıgil, Ahmet; Choi, Mun Young; Kazakov, Andrei; Dryer, Frederick L. (Elsevier BV, 2007-1) The influence of oxygen (O-2) concentration and inert on the sooting and burning behavior of large ethanol droplets under microgravity conditions was investigated through measurements of burning rate, flame temperature, sootshell diameter, and soot volume fraction. The experiments were performed at the NASA Glenn Research Center (GRC) 2.2 s drop tower in Cleveland, OH. Argon (Ar), helium (He), and nitrogen (N-2) were used as the inerts and the O-2 concentration was varied between 21% and 50% mole fraction a...
Low temperature photocatalytic oxidation of carbon monoxide over palladium doped titania catalysts Yetişemiyen, Pelin; Karakaş, Gürkan; Department of Chemical Engineering (2010) The room temperature photocatalytic oxidation of carbon monoxide in excess air was examined over silica/titania and 0.1%palladium/silica/titania catalysts under UV irradiation. The experiments were conducted in batch re-circulated reactor with the initial 1000 ppm carbon monoxide in air and 0.5 g catalyst charge and the conversion of carbon monoxide to carbon dioxide was followed by FT-IR spectro-photometer. The change in gas composition in dark and under 36 Watts of UV irradiation exposed to a catalyst are...
DRIFT studies for the reaction and adsorption of alcohols and isobutylene on acidic resin catalysts and the mechanism of ETBE and MTBE synthesis Doğu, Timur; Aydin, E; Oktar, N; Murtezaoglu, K; Dogu, G (2001-11-14) Diffuse reflectance FT-IR spectra of methanol and ethanol on Amberlyst 15 and on a synthesized acidic resin catalyst indicate that alcohol molecules are adsorbed by forming hydrogen bridges with the -SO3H sites of the catalyst and among themselves. Some of the alcohol molecules were found to be strongly chemisorbed by dissociation of one or two hydrogen atoms. Isobutylene was also found to be strongly adsorbed by forming a bridged structure between the adsorbed alcohol molecules and the -SO3H groups. DRIFT ...

Citation Formats

O. Dernek, “Density functional theory investigation of the reaction mechanisms for selective oxidation of alcohols on gold catalysts,” M.S. - Master of Science, Middle East Technical University, 2016.