Hybrid sulfur cycle

The hybrid sulfur cycle (HyS) is a two-step water-splitting process intended to be used for hydrogen production.

The remaining thermochemical step is shared with the sulfur-iodine cycle.

Current development efforts in the United States are being led by the Savannah River National Laboratory.

The two reactions in the HyS cycle are as follows:[2] Sulfur dioxide acts to depolarize the anode of the electrolyzer.

This results in a significant decrease in the reversible cell potential (and, therefore, the electric power requirement) for reaction (2).