Swedish research separates H from O

A safer method to separate hydrogen and oxygen atoms from water is also easier, according to its developers.

Researchers from Sweden’s KTH Royal Institute of Technology and the Universidad de Alicante in Spain have jointly created a cell that compartmentalises hydrogen and oxygen and prevents mixing.

This, they say, goes beyond existing – and expensive – processes that carefully isolate hydrogen and oxygen from each other using membrane barriers to prevent explosive mixing.

In a typical electrolyser, electric current passes through an electrode, causing a reaction at the cathode (negatively charged end) to produce hydrogen and hydroxide ions. The hydroxide then passes through the membrane where it forms oxygen at the positive anode.

The new method does away with this process by instead using a super capacitive “bifunctional” carbon electrode which can switch between negative and positive states within a two-chambered cell.

This electrode produces hydrogen in the cathodic cell, then releases hydroxide and produces oxygen in the anodic. No electrode degradation was apparent in this process, which the developers hope offers a good process for building a commercial-scale version of their system.

Such a system may also be effectively connected to a renewable energy source, as is the current proposal for many green hydrogen production facilities.

“Since we don’t risk mixing the gases, we can operate over a wider range of input power,” says the study’s first author, Esteban Toledo-Carrillo. “It’s much easier then to couple with renewable energies that generally provides variable power.”

The proposed electrolyser is published in the journal Science Advances.