Generation of hydrogen and oxygen using a PEM electrolyser

Principle

The PEM electrolyser consists of a thin, proton-conducting polymer electrolyte membrane (PEM), the two sides of which are each coated with a catalysing material. These coatings form the anode and the cathode. The theoretical decomposition voltage of water is 1.23 V. This voltage is higher in practice, however, because of losses in the electrolyser. It is about 1.55 V in the electrolyser used here. When this voltage is exceeded, water molecules are decomposed and hydrogen and oxygen are generated.

Benefits

• Experiment is part of a complete solution set with a total of 10 experiments for Renewable Energy fuel-cell technology
• The power supply used is versatile and is particularly suitable for pupil tests for all ages
• Doubled learning success: Electric circuit diagram on top, real components can be seen at the bottom

Tasks

How can hydrogen be generated from water?

Observe what happens when a voltage is applied to the PEM electrolyser.