Novel sulfate solid supported binary Ru-Ir oxides for superior electrocatalytic activity towards OER and CER

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrolysis for hydrogen production requires robust anode materials capable of withstanding diverse electrolyte conditions, including brine, seawater, and pure water.
• Expanding renewable electricity-driven hydrogen production necessitates anode catalysts with high stability and efficiency in various electrochemical environments.

Purpose of the Study:

• To develop and characterize a novel catalyst/support hybrid material for enhanced oxygen evolution reaction (OER) and chlorine evolution reaction (CER) in electrolysis.
• To investigate the electronic structure and catalytic mechanisms of the synthesized material for improved hydrogen production.

Main Methods:

• Synthesis of a binary ruthenium-iridium oxide (Ru_3.5Ir₁O_x) catalyst supported on barium strontium sulfate (BaSrSO₄) via anion ligand exchange.
• Electrochemical performance testing for OER and CER, including overpotential measurements at a current density of 10 mA cm^-2.
• Characterization using X-ray adsorption spectra and theoretical calculations to elucidate electronic structure and catalytic activity.

Main Results:

• The synthesized RuIrO_x/BSS catalyst demonstrated excellent OER and CER performances, achieving 10 mA cm^-2 with low overpotentials of 244 mV and 38 mV, respectively.
• X-ray adsorption spectra revealed an interface charge transfer effect, increasing electron density at Ru and Ir sites.
• Theoretical calculations confirmed that modulated electronic structures of active sites lead to intrinsically high catalytic activity and lower overpotentials.

Conclusions:

• The novel RuIrO_x/BSS catalyst offers a promising solution for durable and efficient anodes in electrolysis systems for hydrogen production.
• The observed interface charge transfer effect and modulated electronic structures are key to the catalyst's superior OER and CER catalytic activity.
• This work provides insights into designing advanced electrocatalysts for electrochemical energy conversion applications.