Synthesis and characterization of ethanol electro-oxidation catalysts

Download

index.pdf

Date

2010

Author

Demir-Kıvrak, Hilal

Metadata

Show full item record

Item Usage Stats

255
views

106
downloads

In this study, the role of defects, the role of Sn in relation to defects, and the role of oxide phase of tin in ethanol electro-oxidation reaction were investigated. Firstly, adsorption calorimetry measurements were conducted on monometallic (1%Pt, 2%Pt, and 5%Pt) and bi-metallic (5% Pt-Sn) γ-Al2O3 supported Pt catalysts. It was observed that while saturation coverage values decreased, intermediate heats remained same for Pt-Sn catalysts by the increasing amount of tin. The effect of particle size was investigated on Pt/C (pH=5), Pt/C (pH=11) catalysts at different scan rates. At high scan rates (quite above diffusion limitations), current per site activities were nearly the same for 20% Pt/C (E-Tek), Pt/C (pH=11), and Pt/C (pH=5) catalysts, which explained as electro-oxidation reaction takes place at the defects sites. Furthermore, the effect of support on ethanol electro-oxidation was investigated on CNT supported Pt catalyst. Results indicate that only the metal dispersions improved ethanol electro-oxidation reaction and support did not have any effect on ethanol electro-oxidation reaction. Results on the 20% Pt-Sn/C (15:1 to 1:1 Pt: Sn atomic ratios) and 20% Pt-SnO2/C (6:1 and 1:1) catalysts indicated that ethanol electro-oxidation activity increased by increasing tin amount. For 20% Pt-Sn/C catalysts, Pt-Sn (6:1)/C indicated best activity. On the other hand, 20% Pt-SnO2 (6:1)/C catalyst was better than Pt-Sn (6:1)/C in terms of ethanol electro-oxidation activity due to the fact that there was low contact between Pt and tin oxide particles.

Subject Keywords

Electrochemistry., Electrolysis.

URI

http://etd.lib.metu.edu.tr/upload/12613887/index.pdf
https://hdl.handle.net/11511/20020

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Syntheses and Electrochemical Characterization of Low Oxidation Potential Nitrogen Analogs of Pedot as Electrochromic Materials Hacioglu, Serife O.; Yigit, Deniz; Ermis, Emel; Soylemez, Saniye; GÜLLÜ, Mustafa; Toppare, Levent Kamil (The Electrochemical Society, 2016-01-01) In this study, the electropolymerization of ethyl andmethyl substituted asymmetrical nitrogen analogs of 3,4-ethylenedioxythiophene (OEt and OMe) were synthesized, characterized and their electrochemical properties were investigated. Both polymers (POEt and POMe) were synthesized electrochemically and characterized using spectroelectrochemical technique to determine optical changes of the resulting polymer films. Electrochemical studies demonstrated that these polymers exhibited a significantly low oxidatio...
Synthesis and characterization of optical, electrochemical and photovoltaic properties of selenophene bearing benzodithiophene based alternating polymers Atli, Gulten Ozkul; Alemdar, Eda; Taşkaya Aslan, Sultan; Udum, Yasemin Arslan; Toppare, Levent Kamil; Çırpan, Ali (Elsevier BV, 2020-04-01) In this study two donor-acceptor type alternating polymers containing electron-deficient benzotriazole moiety and electron-rich selenophene bearing benzodithiophene moiety; P1 and P2, were designed and synthesized via Stille polymerization. Moreover, the effects of thiophene and selenophene as pi-bridges on optical, electrochemical and optoelectronic features of polymers were examined. The optical band gap values of P1 and P2 were found as 1.47 eV and 1.72 eV, respectively. Cyclic voltammetry studies were p...
Synthesis of conducting polymers of terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester and investigation of their electrochromic properties Coşkun, Yelda; Toppare, Levent Kamil; Department of Chemistry (2004) Terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE) was synthesized through the reaction of 2-thiophen-3-yl-ethanol and terepthaloyl chloride. Electrochemical behavior of the TATE and TATE in the presence of thiophene were studied by cyclic voltammetry (CV). The chemical structure of monomer is characterized via Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Homopolymer of TATE was synthesized by galvanostatic and potentiostatic methods, and copolymeri...
Spectroelectrochemical investigation of the anodic oxidation of dibenzo-18-crown-6 Cihaner, A; Önal, Ahmet Muhtar (Elsevier BV, 2004-10-01) Poly(dibenzo-18-crown-6) (poly-DB18C6) was synthesized by electrochemical oxidation of dibenzo-18-crown-6 (DB18C6) using a mixture of acetonitrile and dichloromethane as the solvent and tetrabutylammonium tetrafluoroborate (TBABF(4)) or tetrabutylammonium hexafluorophosphate (TBAPF(6)) as supporting electrolyte. The anodic polymerization of DB18C6 was investigated using in situ ESR and in situ UV-Vis spectroscopic techniques. Spectroelectrochemical (SPEL), properties and thermal analysis of the resulting po...
Synthesis and spectroelectrochemical characterization of multi-colored novel poly(3,6-dithienylcarbazole) derivatives containing azobenzene and coumarin chromophore units Yigit, Deniz; Hacioglu, Serife O.; GÜLLÜ, Mustafa; Toppare, Levent Kamil (Elsevier BV, 2016-04-01) Azobenzene and coumarin units bearing four novel 3,6-linked thiophene-carbazole-thiophene type electroactive monomers were synthesized in order to observe the effects of strong chromophore units on the electrochemical and spectroelectrochemical behaviors of resulting pi-conjugated conducting polymers (PTCbzAz, PECbzAz, PTCbzCo and PECbzCo). Electronic and optoelectronic properties of all polymers were investigated by cyclic voltammetry and in situ spectroelectrochemical studies, and their oxidation potentia...

Citation Formats

H. Demir-Kıvrak, “Synthesis and characterization of ethanol electro-oxidation catalysts,” Ph.D. - Doctoral Program, Middle East Technical University, 2010.