Hydrogen Purification through a Highly Stable Dual-Phase Oxygen-Permeable Membrane

Area of Science:

• Materials Science
• Chemical Engineering
• Energy Technology

Background:

• Oxygen permeable membranes (OPMs) offer a promising route for high-purity hydrogen production via water splitting.
• Existing cobalt- and iron-based OPMs suffer from chemical instability under reducing atmospheres, limiting their application.
• Over-reduction of metal ions in current OPMs leads to degradation and reduced performance in hydrogen purification processes.

Purpose of the Study:

• To develop a novel dual-phase membrane with enhanced chemical stability for hydrogen purification.
• To investigate the performance of a cerium-praseodymium oxide and praseodymium-strontium-magnesium-titanate composite membrane (CPO-PSM-Ti) under reducing conditions.
• To overcome the limitations of existing OPMs in upgrading low-purity hydrogen.

Main Methods:

• Fabrication of a dual-phase membrane: Ce$_{0.9}$ Pr$_{0.1}$ O$_{2-δ}$ -Pr$_{0.1}$ Sr$_{0.9}$ Mg$_{0.1}$ Ti$_{0.9}$ O$_{3-δ}$ (CPO-PSM-Ti).
• High-temperature testing of the membrane for hydrogen purification at 940°C.
• Evaluation of membrane stability through prolonged operation (180 hours) under reducing atmospheres.

Main Results:

• The CPO-PSM-Ti membrane demonstrated excellent chemical stability and mixed oxygen ionic-electronic conductivity.
• An acceptable hydrogen production rate of 0.52 mL min⁻¹ cm⁻² was achieved at 940°C.
• The membrane exhibited robust stability with no obvious degradation during 180 hours of continuous operation.

Conclusions:

• The developed CPO-PSM-Ti dual-phase membrane shows significant advantages over existing OPMs for upgrading low-purity hydrogen.
• Its superior chemical stability and mixed conductivity make it a promising candidate for efficient and durable hydrogen purification.
• This advancement contributes to the development of advanced materials for clean energy applications.