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Full-Text Articles in Chemistry

Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li Aug 2014

Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li

Journal of Electrochemistry

Two-dimensional flower-like Pt nanostructures (2D FPNs) were fabricated on glassy carbon substrates by galvanostatical electrochemical technique. The electrolyte was the HAuCl4 + HClO4 aqueous solution without addition of any structure-directing organic reagent, which made as-prepared Pt nanostructures cleaner, exhibiting much higher reactivity. Scanning electron microscopic images revealed that 2D FPNs were spherical Pt nano-flowers constructed by the smallest building blocks, nano-leaves. The number density of spherical Pt nano-flowers can be tuned by controlling the electrodeposition time. High resolution transmission electron microscopic images indicated that each nano-leaf was formed by growing along Pt(111) direction. Electrocatalytic activities of as-prepared 2D …


Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor Aug 2013

Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor

Graduate Theses and Dissertations

Platinum and Pt alloys are among the most important heterogeneous catalysts for many organic reactions and electrochemical reactions associated with the fuel cell technologies. How to reduce Pt usage while maintaining the performance of the catalysts becomes a subject for intensive research in materials chemistry. For heterogeneous catalysis, the catalytic reactivity and selectivity are strongly correlated with different crystallographic facets exposed on the surface. The facets with high-index planes whose Miller indices with at one is larger than unity are generally more active than those with low-index planes (e.g., {100}, {111}, and {110}). Tuning the morphology of the nanoparticles to …


Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong Dec 2012

Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong

Journal of Electrochemistry

Adsorbed sulfur is commonly considered as a reaction poison. However, small amounts of sulfur on platinum significantly increase the surface reactivity toward carbon monoxide (CO) electrooxidation. For the solution CO oxidation, the onset potential was shifted up to over 300 mV negative to that on S-free surface, and the extent of the negative potential shift increases with the sulfur coverage (Xs) up to about 0.6. The enhanced CO oxidation also depends on the solution pH. For the adsorbed CO, at low sulfur coverages (Xs < 0.3), the oxidation peak potential is about 40 mV negative to that of the corresponding clean Pt. However, at higher coverages, the peak potential is about 30 mV more positive. Surface-enhanced Raman spectra show that the adsorption of sulfur significantly redshifts the Pt-CO stretching frequency. These observations are explained by the weakening of the Pt-CO bond and the hindrance of CO diffusion by Sads.


In Situ Surface-Enhanced Raman Scattering Spectroscopic Study Of Sulfur Adsorption On Polycrystalline Platinum Electrode Surface, Bolian Xu-, In-Su Park, Ying Li, De-Jun Chen, Yuye J. Tong Aug 2010

In Situ Surface-Enhanced Raman Scattering Spectroscopic Study Of Sulfur Adsorption On Polycrystalline Platinum Electrode Surface, Bolian Xu-, In-Su Park, Ying Li, De-Jun Chen, Yuye J. Tong

Journal of Electrochemistry

The paper reports the first in situ surface enhanced Raman scattering (SERS) spectroelectrochemistry study of sulfur adsorption and electro-oxidation on highly roughened polycrystalline Pt surface in both acidic and basic supporting electrolytes. The SERS spectra were taken at a constant electrode potential after accumulative electro-oxidation CVs of the Pt electrode with pre-adsorbed sulfur species and at different electrode potentials that were varied stepwise of the Pt electrode immersed in sulfur-containing electrolytes without pre-adsorbed sulfur species. In both cases,a dominant vibrational band at 299 cm -1 in acidic electrolyte but at 310 cm-1 in basic electrolyte was observed,which was assigned to …


Design And Development Of Highly Active, Nanoengineered, Platinum Based Core-Shell Electrodes For Proton Exchange Membrane Fuel Cells, Seth Louis Knupp Jan 2010

Design And Development Of Highly Active, Nanoengineered, Platinum Based Core-Shell Electrodes For Proton Exchange Membrane Fuel Cells, Seth Louis Knupp

Legacy Theses & Dissertations (2009 - 2024)

Highly active nanoengineered core-shell electrocatalyst have a great potential to be used as fuel cell electrodes. They can alleviate problems related with commercial carbon supported platinum by simultaneously lowering cost while enhancing reaction kinetics and overall performance. More recently, use of nanoengineered core-shell electrode structures have showed their ability to enhance the stability and overall lifetime of the catalyst without sacrificing the electrode's performance. We studied the potential of using highly active core-shell nanoparticles supported on carbon nanomaterials as fuel cell electrodes.


Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding Aug 2008

Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding

Journal of Electrochemistry

The nanoporous gold(NPG) electrodes with uniform pore sizes and ligaments were prepared by using a simple dealloying method.The as-prepared NPG showed high catalytic activity towards the oxidation of formic acid and formaldehyde.After tiny amount of platinum was deposited onto the NPG substrate,not only the structure stability of NPG was greatly improved,but also the Pt-Au bimetallic catalysts displayed the better catalytic activity and the stronger poison resistance towards the electrooxidation of small organic molecules than the bulk platinum due to synergistic effect between Au and Pt compositions.


Confocal Microprobe Raman Spectroscopy For Investigating The Electrochemical Interface, Bin Ren, Feng Ming Liu, Xufeng Lin, Zhong-Qun Tian Feb 2001

Confocal Microprobe Raman Spectroscopy For Investigating The Electrochemical Interface, Bin Ren, Feng Ming Liu, Xufeng Lin, Zhong-Qun Tian

Journal of Electrochemistry

The invention of the surface enhanced Raman spectroscopy (SERS) in the mid of 1970s, opened an entirely new and very promising area. However, it was found that SERS of practical application in electrochemistry can only be found on noble metal surfaces, such as Ag, Au and Cu that exhibit huge surface enhancement [1] . This greatly limits the application of SERS in electrochemistry. In electrocatalysis, corrosion inhibition, sensor, and power source, the most widely used materials are Pt, Fe and Ni and their alloys as well as Si. Thus, it is of great significance to extend surface Raman study to …