Approach to Evaluation of Electrocatalytic Water Splitting Parameters, Reflecting Intrinsic Activity: Toward the Right Pathway

• Published in: ChemSusChem Vol. 16; no. 11; pp. e202202126 - n/a
• Main Authors: Nazari, Mahrokh, Ghaemmaghami, Mostafa
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 09.06.2023
• Subjects: Current density; Electrocatalysts; electrocatalytic activity; electrochemically active surface area; Energy storage; intrinsic activity; Parameters; specific activity; Transition metals; turnover frequency; Water splitting; electrocatalytic activity; intrinsic activity; specific activity; turnover frequency; electrochemically active surface area
• ISSN: 1864-5631; 1864-564X; 1864-564X
• DOI: 10.1002/cssc.202202126

The development of transition metal‐based non‐precious‐metal electrocatalysts for energy storage and conversion systems has received a lot of interest recently. To further this subject in the proper way given the development of electrocatalysts, a fair comparison of their respective performance is necessary. This Review investigates the parameters used for the comparison of electrocatalyst activity. Significant evaluation criteria employed in electrochemical water splitting studies are the overpotential at defined current density usually at 10 mA per geometric surface area, Tafel slope, exchange current density, mass activity, specific activity and turnover frequency (TOF). This Review will discuss how to identify the specific activity and TOF by electrochemical and non‐electrochemical methods to represent intrinsic activity as well as the benefits and uncertainties of each technique, ensuring that each method is applied correctly when calculating intrinsic activity metrics. Do it properly: Electrochemical water splitting is considered as the most promising technology for clean hydrogen production with two important half‐reactions involved in water splitting, hydrogen evolution reaction and oxygen evolution reaction. To progress this topic in the right direction, a fair comparison of their intrinsic activities is required, which this Reviews attempts to achieve.