Electrochemical Active Surface Area Determination of Iridium‐Based Mixed Oxides by Mercury Underpotential Deposition

2021 ◽  
Author(s):  
Silvia Duran ◽  
Marine Elmaalouf ◽  
Mateusz Odziomek ◽  
Jean‐Yves Piquemal ◽  
Marco Faustini ◽  
...  
1997 ◽  
Vol 42 (3) ◽  
pp. 493-495 ◽  
Author(s):  
A.N. Correia ◽  
L.H. Mascaro ◽  
S.A.S. Machado ◽  
L.A. Avaca

2020 ◽  
Vol 234 (5) ◽  
pp. 979-994 ◽  
Author(s):  
Paula Connor ◽  
Jona Schuch ◽  
Bernhard Kaiser ◽  
Wolfram Jaegermann

AbstractIn the last decades several different catalysts for the electrochemical water splitting reaction have been designed and tested. In so-called benchmark papers they are compared with respect to their efficiency and activity. In order to relate the different catalyst to each other the definition of well-defined procedures is required. Two different methods are mainly used: Either the normalization with respect to the geometric surface area or to the catalyst loading. Most often only one of these values is available for a sample and the other one cannot be estimated easily. One approach in electrocatalysis is to determine the Helmholtz double layer capacitance (DLC) and deduce the electrochemical active surface area (ECSA). The DLC can be obtained from two different methods, either using differential capacitance measurement (DCM) or impedance spectroscopy (EIS). The second value needed for the calculation of the ECSA is the specific capacitance, which is the capacitance for a perfectly flat surface of given catalyst material. Here, we present the determination of the different capacitance values using manganese oxide as the exemplary model for the oxygen evolution reaction (OER). We determine the capacitance by DCM and EIS to calculate the ECSA using literature values for the specific capacitance. The obtained values are comparable from the two methods, but are much larger than the surface areas obtained by atomic force microscopy. Therefore, we consider the possibility of using the measured AFM area together with the Helmholtz capacitance to determine the specific capacitances for this material class. The comparison of these results with literature values illustrates the actual limits of the ECSA method, which will be discussed in this paper.


2009 ◽  
Vol 15 (S2) ◽  
pp. 324-325
Author(s):  
M Lundberg ◽  
P Stanley Jørgensen ◽  
JR Bowen ◽  
Å Persson ◽  
AK Srivastava ◽  
...  

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 426C-426
Author(s):  
M.K. Upadhyaya ◽  
N.H. Furness

Surface area of cucumbers, carrots, parsnips, and beets was determined using the following non-destructive methods: Baugerod's method, Baugerod's method with inclusion of a factor correcting for substitution of weight for volume in the formula, and a novel image analysis method. Accuracy of the methods was ascertained by comparison with a direct shrink-wrap replica method of surface area measurement. Vegetables ranged in shape from cylindrical (cucumber and carrot) to conical (parsnip and beet). No difference in accuracy among methods of surface area determination was detected for carrots or beets. Baugerod's method and the image analysis technique differed significantly from the direct shrink-wrap replica technique for surface area determination of parsnips and cucumbers, respectively. Inclusion of a correction factor in Baugerod's method did not increase the accuracy of this method for any of the vegetables. The precision and repeatability of each method was determined by repeated measures analysis. Baugerod's method lost precision and repeatability for the conically shaped vegetables. Conversely, the shrink-wrap replica method lost precision and repeatability for the cylindrically shaped vegetables. The image analysis technique was precise and highly repeatable over the range of vegetable shapes. The development of a rapid, accurate, and precise non-destructive method of surface area measurement using image analysis techniques will provide a useful tool in the physiological study of vegetable products. Applicability of such a method over a range of vegetable shapes will be of additional value.


Sign in / Sign up

Export Citation Format

Share Document