IrPd Nanoalloy-Structured Bifunctional Electrocatalyst for Efficient and pH-Universal Water Splitting.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for large-scale green hydrogen production via water splitting.
• Current bifunctional electrocatalysts often lack high efficiency and pH universality for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).

Purpose of the Study:

• To develop a highly efficient and pH-universal bifunctional electrocatalyst for water splitting.
• To investigate the performance of an iridium-palladium (IrPd) electrocatalyst supported on ketjenblack for both HER and OER.

Main Methods:

• Synthesis of an IrPd electrocatalyst supported on ketjenblack.
• Electrochemical characterization of the catalyst for HER and OER performance.
• Testing the catalyst in an anion exchange membrane electrolyzer for water decomposition.

Main Results:

• The optimized IrPd catalyst shows specific activities of 4.46 A mg_Ir^-1 for HER and 3.98 A mg_Ir^-1 for OER at 100 mV and 370 mV overpotential, respectively, in alkaline conditions.
• The Ir₄₄Pd₅₆/KB catalyst demonstrated stability exceeding 20 hours at 250 mA cm^-2 in an anion exchange membrane electrolyzer.
• The catalyst exhibits outstanding bifunctional performance across a wide range of pH conditions.

Conclusions:

• The developed IrPd electrocatalyst offers a promising solution for efficient and stable water splitting.
• This work provides insights into designing advanced bifunctional electrocatalysts by tuning metal site microenvironments and electronic structures.