Active surface area in oxide electrodes by overpotential deposited oxygen species for the oxygen evolution reaction

1996 ◽  
Vol 26 (5) ◽  
pp. 515-521 ◽  
Author(s):  
J. C. K. Ho ◽  
D. L. Piron
Keyword(s):  
Surface Area ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Surface ◽  
Active Surface Area ◽  
Oxygen Species ◽  
Oxide Electrodes

Comparison of the effects of cation and phosphorus doping in cobalt-based spinel oxides towards the oxygen evolution reaction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Lili Yao ◽  
Wenxiu Yang ◽  
Yongjian Niu ◽  
Jiming Liu ◽  
Shun Zhang ◽  
...  
Keyword(s):  
Surface Area ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Oxygen Vacancies ◽  
Active Surface ◽  
Active Surface Area ◽  
Phosphorus Doping ◽  
Electrochemically Active ◽  
Spinel Oxides ◽  
Electrochemically Active Surface

Phosphorus incorporation further boosted the OER activity of cation-doped Co-based spinel oxides via remarkably tuning the oxygen vacancies, crystallinity and electrochemically active surface area on the surface.

scholarly journals Hexadecyltrimethylammonium hydroxide promotes electrocatalytic activity for the oxygen evolution reaction

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Yugan Gao ◽  
Chengqi Wu ◽  
Sen Yang ◽  
Yiwei Tan
Keyword(s):  
Surface Area ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Surface ◽  
Ammonia Borane ◽  
Absolute Number ◽  
Alkaline Electrolyte ◽  
Active Surface Area ◽  
Electrochemically Active ◽  
Electrochemically Active Surface

Abstract The oxygen evolution reaction is an essential factor in many renewable energy technologies, such as water splitting, fuel cells, and metal–air batteries. Here we show a unique solution to improve the oxygen evolution reaction rate by adjusting the electrolyte composition via the introduction of hexadecyltrimethylammonium hydroxide into an alkaline electrolyte. The strong adsorption of hexadecyltrimethylammonium cations on the surface of electrocatalysts provides the increased absolute number of OH− ions near the electrocatalyst surface, which effectively promotes the oxygen evolution reaction performance of electrocatalysts, such as Fe1−yNiyS2@Fe1−xNixOOH microplatelets and SrBaNi2Fe12O22 powders. Meanwhile, we present an electrochemical conditioning approach to engineering the electrochemically active surface area of electrocatalysts, by which the resultant Fe1−yNiyS2@Fe1−xNixOOH microplatelets have a larger electrochemically active surface area after the electrochemical conditioning of the as-synthesized Fe1−yNiyS2 microplatelets using ammonia borane than those obtained after the conventional electrochemical conditioning without ammonia borane, presumably due to the appropriate conversion rate of Fe1−xNixOOH shells.

scholarly journals Highly efficient oxygen evolution reaction via facile bubble transport realized by three-dimensionally stack-printed catalysts

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ye Ji Kim ◽  
Ahyoun Lim ◽  
Jong Min Kim ◽  
Donghoon Lim ◽  
Keun Hwa Chae ◽  
...  
Keyword(s):  
Surface Area ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Specific Activity ◽  
Theoretical Calculations ◽  
Nanostructured Catalysts ◽  
Building Blocks ◽  
Utilization Efficiency ◽  
Active Surface Area ◽  
Mass Activity

Abstract Despite highly promising characteristics of three-dimensionally (3D) nanostructured catalysts for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolyzers (PEMWEs), universal design rules for maximizing their performance have not been explored. Here we show that woodpile (WP)-structured Ir, consisting of 3D-printed, highly-ordered Ir nanowire building blocks, improve OER mass activity markedly. The WP structure secures the electrochemically active surface area (ECSA) through enhanced utilization efficiency of the extended surface area of 3D WP catalysts. Moreover, systematic control of the 3D geometry combined with theoretical calculations and various electrochemical analyses reveals that facile transport of evolved O2 gas bubbles is an important contributor to the improved ECSA-specific activity. The 3D nanostructuring-based improvement of ECSA and ECSA-specific activity enables our well-controlled geometry to afford a 30-fold higher mass activity of the OER catalyst when used in a single-cell PEMWE than conventional nanoparticle-based catalysts.

scholarly journals Characterization and Electrocatalytic Properties of Titanium-Based Ru0.3Co0.7−xCexMixed Oxide Electrodes for Oxygen Evolution in Alkaline Solution

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Hongjun Wu ◽  
Qin Ruan ◽  
Li Li ◽  
Baohui Wang
Keyword(s):  
Oxygen Evolution ◽  
Electrocatalytic Activity ◽  
Strong Dependence ◽  
Sol Gel ◽  
Active Surface ◽  
Catalytic Performance ◽  
Open Circuit ◽  
Active Surface Area ◽  
Oxide Electrodes ◽  
Sol Gel Process

Ti-supported RuO2-Co3O4-CeO2(Ru0.3Co0.7−xCexoxide,0≤x≤0.7) electrodes were prepared by sol-gel process. The phase structure, surface morphology, and microstructure of the oxide layer were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrocatalytic activity and oxygen evolution reaction (OER) kinetics on these electrodes in 1.0 mol⋅dm−3KOH solution were studied by recording open-circuit potential, cyclic voltammetry, and polarisation curves. The results showed that the appropriate content of CeO2could reduce the grain size and increase active surface area. The electrocatalytic activity shows a strong dependence on the CeO2content in the film. Catalytic performance of mixed oxide electrodes with 40 mol % CeO2was the best, with the greatest voltammetric charge, 86.23 mC⋅cm−2, and the smallest apparent activation energy for OER at 0.60 V was 22.76 kJ⋅mol−1.

scholarly journals The Determination of Electrochemical Active Surface Area and Specific Capacity Revisited for the System MnOx as an Oxygen Evolution Catalyst

2020 ◽  
Vol 234 (5) ◽  
pp. 979-994 ◽  
Author(s):  
Paula Connor ◽  
Jona Schuch ◽  
Bernhard Kaiser ◽  
Wolfram Jaegermann
Keyword(s):  
Specific Capacitance ◽  
Surface Area ◽  
Oxygen Evolution ◽  
Specific Capacity ◽  
Active Surface ◽  
Capacitance Measurement ◽  
Catalyst Loading ◽  
Active Surface Area ◽  
Electrochemical Active Surface Area

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.

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

High Surface Area NiCoP Nanostructure as Efficient Water Splitting Electrocatalyst for the Oxygen Evolution Reaction

2021 ◽  
pp. 111312
Author(s):  
Sisir Maity ◽  
Dheeraj Kumar Singh ◽  
Divya Bhutani ◽  
Suchitra Prasad ◽  
Umesh V. Waghmare ◽  
...  
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Surface ◽  
High Surface Area

Increasing Active Surface Area to Fabricate Ultra-Hydrophobic Surface by Using “Black Silicon” with Bosch Etching Process

2012 ◽  
Vol 12 (6) ◽  
pp. 4919-4927 ◽  
Author(s):  
Nithi Atthi ◽  
Jakrapong Supadech ◽  
Gaetan Dupuy ◽  
On-uma Nimittrakoolchai ◽  
Apirak Pankiew ◽  
...  
Keyword(s):  
Surface Area ◽  
Hydrophobic Surface ◽  
Active Surface ◽  
Etching Process ◽  
Black Silicon ◽  
Active Surface Area
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