Corrosion of copper in distilled water without O2 and the detection of produced hydrogen

• Cu reacts with water producing hydrogen as a by-product.
• Hydrogen is present at depths in the copper substrate well below that of oxygen.
• The reaction product formed in air at 350 °C is more stable than formed in water.

This paper reports on hydrogen pressures measured during ∼19,000 h immersion of copper in oxygen-free liquid distilled water. Copper corrosion products have been examined ex-situ by SEM and characterized by XPS and SIMS. XPS strongly indicates a corrosion product containing both oxygen and hydrogen. SIMS shows that oxygen is mainly present in the outer 0.3 μm surface region and that hydrogen penetrates to depths well below the corrosion product. Thermal desorption spectroscopy shows that the reaction product formed near room-temperature is less stable than that formed in air at 350 °C.