Lab: yeast stores hydrogen in alcohols; iron releases it with light

A flask of baker’s yeast could become part of a hydrogen storage system. Researchers from Tohoku University, Hokkaido University and Kyushu University have demonstrated a cycle in which yeast helps lock hydrogen into an alcohol, while light and iron ions release it again.

The chemistry avoids a sequence used in conventional storage. Instead of producing hydrogen, purifying it, compressing it and then adding it to a carrier molecule, the team uses yeast, water and NADH—a coenzyme involved in fermentation—to transform a polyketone directly into a hydrogen-rich polyhydric alcohol. The alcohol is a liquid organic hydrogen carrier, or LOHC, meaning it stores hydrogen through reversible chemical reactions.

Recovery uses light. In the presence of iron ions, irradiation converts the polyhydric alcohol back into the original polyketone and releases hydrogen. Iron is inexpensive and abundant in Earth’s crust, giving the proposed process a route away from precious-metal catalysts commonly used for this step.

The practical shift is straightforward: hydrogen could be handled through an organic liquid rather than as compressed gas, while the storage step would combine biological catalysts with more abundant materials. That could matter for systems seeking a recyclable way to produce, store and transport hydrogen from sustainable resources.

The limits are equally clear. The work, published in the Journal of Materials Chemistry A, is a laboratory demonstration, not a deployed storage product. The team is still testing more suitable alcohols, including ethylene glycol, and working to improve hydrogen storage and release for practical use.