Water Electrolysis in Saturated Phosphate Buffer at Neutral pH.

Area of Science:

• Electrochemistry
• Sustainable Energy
• Materials Science

Background:

• Hydrogen production via water electrolysis is key for renewable energy, but current methods face economic challenges.
• Existing electrolyzers often operate at extreme acidic or alkaline pH, limiting their widespread adoption.
• Developing cost-effective and efficient water electrolysis is crucial for a sustainable hydrogen economy.

Purpose of the Study:

• To evaluate water electrolysis at neutral pH (pH 7) as a potentially more economical and sustainable approach.
• To investigate the impact of concentrated buffer electrolytes on mass-transport losses.
• To assess the performance and stability of neutral pH electrolysis using model electrodes.

Main Methods:

• Physicochemical properties of concentrated buffer electrolytes were analyzed at varying temperatures and molalities.
• Water electrolysis performance was tested using iridium oxide (IrO_x) anodes and platinum (Pt) cathodes.
• Mass-transport losses were quantitatively determined under different conditions.

Main Results:

• Optimal conditions for minimizing mass-transport losses were identified in saturated K-phosphate solutions at 80°C and 100°C.
• Water electrolysis performance at neutral pH was comparable to that achieved at extreme pH.
• Enhanced stability was observed with the concentrated buffer electrolyte.

Conclusions:

• Neutral pH water electrolysis using concentrated buffer solutions is a viable and promising technology.
• This approach offers comparable performance to traditional methods with potential economic and stability advantages.
• Further research into these electrolytes could accelerate the transition to sustainable hydrogen production.