High-throughput bubble screening method for combinatorial discovery of electrocatalysts for water splitting

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High-throughput screening is crucial for discovering new electrocatalysts for energy applications.
• Traditional electrochemical methods are slow due to serial measurements.
• Existing parallel screening techniques have limitations, especially across a wide pH range.

Purpose of the Study:

• To develop a novel, high-throughput parallel screening method for electrocatalyst discovery.
• To overcome the limitations of existing screening techniques, particularly pH dependency.
• To rapidly identify active electrocatalyst compositions in a large material library.

Main Methods:

• A custom electrochemical cell was designed to image oxygen and hydrogen bubbles produced during water splitting (oxygen evolution reaction and hydrogen evolution reaction).
• Bubble intensity transients were quantitatively analyzed to derive a figure of merit (FOM) representing reaction rate.
• The method was applied to screen a pseudoternary (Ni-Fe-Co)Ox material library with 231 compositions.

Main Results:

• The bubble imaging method successfully screened 231 electrocatalyst compositions in under one minute.
• The screening results showed excellent agreement with traditional, serial electrochemical characterization.
• The developed method is independent of solution pH, making it broadly applicable.

Conclusions:

• A simple, highly parallel, and pH-independent bubble imaging technique can accelerate electrocatalyst discovery.
• This method significantly enhances throughput for identifying active catalyst regions.
• The approach is generalizable for screening electrocatalysts in various energy-related applications.