Effect of platinum surface oxides on the rate of anodic evolution of oxygen in solutions of sulphuric acid

1973 ◽  
Vol 38 (1) ◽  
pp. 29-41 ◽  
Author(s):  
O. Špalek ◽  
J. Balej
Keyword(s):  
Sulphuric Acid ◽  
Platinum Surface ◽  
Surface Oxides ◽  
Evolution Of Oxygen

THE ELECTRODE BEHAVIOR OF PLATINUM

1953 ◽  
Vol 31 (7) ◽  
pp. 665-672
Author(s):  
A. K. Wiebe ◽  
C. A. Winkler
Keyword(s):  
Sulphuric Acid ◽  
Saturated Calomel Electrode ◽  
Platinum Electrodes ◽  
Platinum Surface ◽  
Surface Areas ◽  
The Times

A potential of −0.305 ± 0.005 volt (relative to a saturated calomel electrode) was obtained at a freshly prepared platinum surface within 30 sec. of immersion in oxygen-free N/5 sulphuric acid saturated with hydrogen. In electrolytes saturated with nitrogen or oxygen potentials of +0.05 ± 0.01 volt and +0.745 ± 0.005 volt respectively were more slowly attained. The times required for the electrode to reach maximum potentials, tmax, when it was made a cathode, and corresponding values of tmax when it was rendered anodic, were determined over a range of currents. The values of tmax appear to provide a method of determining the surface areas of platinum electrodes.

Catalytic Duality of Platinum Surface Oxides in the Oxygen Reduction and Hydrogen Oxidation Reactions

2017 ◽  
Vol 8 (4) ◽  
pp. 301-310 ◽  
Author(s):  
Sadaf Tahmasebi ◽  
Ashley A. McMath ◽  
Julia van Drunen ◽  
Gregory Jerkiewicz
Keyword(s):  
Oxygen Reduction ◽  
Hydrogen Oxidation ◽  
Oxidation Reactions ◽  
Platinum Surface ◽  
Surface Oxides

Redox titration of gold and platinum surface oxides at porous microelectrodes

2017 ◽  
Vol 19 (34) ◽  
pp. 22915-22925 ◽  
Author(s):  
Mareike Haensch ◽  
Julian Behnken ◽  
Luis Balboa ◽  
Alexander Dyck ◽  
Gunther Wittstock
Keyword(s):  
Platinum Nanoparticles ◽  
Scanning Electrochemical Microscopy ◽  
Nanoporous Gold ◽  
Platinum Surface ◽  
Redox Titration ◽  
Supported Platinum ◽  
Surface Oxides ◽  
Electrochemical Microscopy

Cavity-microelectrodes were used to investigate surface oxides on supported platinum nanoparticles and nanoporous gold with the surface interrogation mode of scanning electrochemical microscopy.

The effect of Cobalt on the Kinetics of Oxygen evolution at a Lead Dioxide anode in Sulphuric Acid

1959 ◽  
Vol 12 (2) ◽  
pp. 127 ◽  
Author(s):  
DFA Koch
Keyword(s):  
Sulphuric Acid ◽  
Oxygen Evolution ◽  
Current Density ◽  
Lead Dioxide ◽  
Kinetic Constants ◽  
Kcal Mole ◽  
Lead Dioxide Anode ◽  
Kinetics Of ◽  
Evolution Of Oxygen ◽  
Rate Determining Steps

The overpotential (n)-log current density (log i) curves for the evolution of oxygen at a lead dioxide anode in 2N H2SO4 both in the absence and presence of cobaltous sulphate in solution have been used to determine the electrode kinetic constants α ; i0 for a series of temperatures and also ΔH0*:. At 25 �C in the absence of cobalt α=O.59, i0= 10-11, and ΔH0*= 15 kcal mole-1 When 13 mg/l cobaltous sulphate is added α= 1.0, i0= 10-15, and ΔH0*:=29 kcal mole-1. Possible mechanisms for the reaction are discussed on the basis of these values and the rate determining steps suggested (where M represents the PbO2 surface) are M +H2O =MOH +H+ +e in the absence of cobalt and 2CoOH++ = 2Co++ +H2O + O in its presence.

Probing the Dynamics of Platinum Surface Oxides in Fuel Cell Catalyst Layers Using in Situ X-ray Diffraction

2019 ◽  
Vol 2 (11) ◽  
pp. 7772-7780 ◽  
Author(s):  
Isaac Martens ◽  
Raphael Chattot ◽  
Miika Rasola ◽  
Maria Valeria Blanco ◽  
Veijo Honkimäki ◽  
...  
Keyword(s):  
Fuel Cell ◽  
X Ray Diffraction ◽  
Platinum Surface ◽  
X Ray ◽  
Fuel Cell Catalyst ◽  
Catalyst Layers ◽  
Surface Oxides

The Interaction between Human Osteoblastic Cells and Titanium Anodized with Sulphuric Acid Coated or not with Human Plasma Fibronectin

2008 ◽  
Vol 396-398 ◽  
pp. 389-392
Author(s):  
Aline Raybolt dos Santos ◽  
Fernando Costa e Silva ◽  
Gloria Dulce de Almeida Soares
Keyword(s):  
Sulphuric Acid ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Osteoblast Cells ◽  
Cellular Behavior ◽  
Commercially Pure ◽  
Surface Oxides ◽  
Human Osteoblastic Cells

In this study, commercially pure titanium (Ti-cp) sheets grade 2 were used as substrates. To investigate the role of composition and characteristics of titanium surface oxides in cellular behavior of osteoblasts, the surface of titanium were modified by anodic oxidation with sulphuric acid. Subsequently were treated part of anodized samples with FN and cultured with osteoblast cells for 30, 120 and 240 minutes. The chemical composition and topography have influenced the interaction between fibronectin and substrate. Cells were found more associated to the surfaces that have been submitted to anodization and FN coating than to the related controls.

A non-cyanide method of electropolishing silver

1978 ◽  
Vol 36 (1) ◽  
pp. 146-147
Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger
Keyword(s):  
Electron Microscopy ◽  
Sulphuric Acid ◽  
Methyl Alcohol ◽  
Health Hazards ◽  
Silver Alloy ◽  
High Quality ◽  
Silver Alloys ◽  
Free Sample ◽  
Specimen Quality ◽  
Standard Techniques

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).

Ultrathin Platinum Crystal Surface Structures

1985 ◽  
Vol 43 ◽  
pp. 394-395
Author(s):  
R. L. Hines
Keyword(s):  
Crystal Surface ◽  
Surface Structures ◽  
Platinum Surface ◽  
Platinum Surfaces ◽  
Resolution Level ◽  
Experimental Facilities ◽  
Carbon Backing ◽  
Mesh Grid ◽  
Atom Layer

The importance of atom layer terraces or steps on platinum surfaces used for catalysis as discussed by Somorjai justifies an extensive investigation of the structure of platinum surfaces through electron microscopy at the atomic resolution level. Experimental and theoretical difficulties complicate the quantitative determination of platinum surface structures but qualitative observation of surface structures on platinum crystals is now possible with good experimental facilities.Ultrathin platinum crystals with nominal 111 orientation are prepared using the procedure reported by Hines without the application of a carbon backing layer. Platinum films with thicknesses of about ten atom layers are strong enough so that they can be mounted on grids to provide ultrathin platinum crystals for examination of surface structure. Crystals as thin as possible are desired to minimize the theoretical difficulties in analyzing image contrast to determine structure. With the current preparation procedures the crystals frequently cover complete openings on a 400 mesh grid.

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