Pure water type (PEM electrolysis): Only pure water is electrolyzed, no alkaline substances are added. A titanium alloy electrolytic cell and a stainless steel gas path structure are adopted. The advantages include high hydrogen purity (≥99.999%), low power consumption (about 150W), zero pollution, but the costs of PEM membranes and catalysts are relatively high.
Alkaline type (liquid electrolysis): Uses KOH solution (concentration 10%-30%) as the electrolyte, and the reaction is catalyzed by noble metal electrodes. The cost is relatively low, but the efficiency is limited. The electrolyte needs to be replaced regularly, and the purity of hydrogen depends on subsequent purification (such as pressure swing adsorption).
