A new electrochemical process developed by researchers at the Technion, Israel Institute of Technology, could make green hydrogen production more economically attractive by producing a valuable industrial chemical alongside the fuel.
The approach replaces the oxygen normally produced during water electrolysis with an epoxide, a class of chemicals commonly used to make polymers, coatings, adhesives, pharmaceuticals and other products. Researchers report that the system achieved 98% efficiency in both hydrogen production and the parallel epoxide-producing reaction.
The study, published in Nature communicationwas led by Prof. Avner Rothschild from the Technion Faculty of Materials Science and Engineering and Dr. Guilin Ruan, a postdoctoral researcher. The team filed a US patent application for the technology.
Replacing oxygen with a valuable chemical
Green hydrogen is produced by using electricity from renewable sources to split water into hydrogen and oxygen. While the resulting hydrogen can help decarbonize industries that are difficult to electrify directly, its wider adoption is limited by its cost compared to hydrogen made from fossil fuels.
The Technion team approached the problem by considering what happens on the other side of the electrolysis process. “Instead of producing oxygen,” the researchers tried to create an epoxide, converting what would normally be a byproduct into a potentially valuable chemical raw material.
In their experiments, the researchers report an efficiency of 98% for both hydrogen production and parallel epoxide synthesis. This means, the team says, that only about 2% of the electrical charge was lost through competing reactions. The researchers also report that a current density is achieved that they believe is compatible with large-scale electrolysis.
Membrane-free electrolysis
The process builds on previous work by Rothschild and his collaborators, who separated the electrochemical reactions that normally produce hydrogen and oxygen.
This concept forms the basis of membrane-free electrolysis, which avoids the membrane traditionally used to separate the two electrode reactions. H2Pro has commercialized an earlier technology from the research group.
The new system takes the concept in a different direction by combining hydrogen production with chemical synthesis. According to Ruan, the performance comes from optimizing the entire electrochemical system rather than focusing on a single electrode or reaction.
The system combines the electrodes, a redox mediator, the solvent environment and the operating configuration. This allows the researchers to produce hydrogen and epoxy without a membrane separating the electrodes.
A potential economic advantage
The approach could provide additional economic incentive for green hydrogen production as the electrolysis process would produce two useful products instead of hydrogen and oxygen alone.
However, the reported results come from the researchers’ experiments and the study does not prove that the technology is ready for commercial use. While the reported current density is described as compatible with large-scale electrolysis, further development is required to show how the process performs under sustained industrial operating conditions.
The European Research Council supported research under the H2Bro project following Rothschild’s ERC Advanced Grant in 2023. It is also part of the inter-university research initiative “Waste to Value” funded by the Israel Council for Higher Education.
The researchers have filed a U.S. patent application for the technology, suggesting they see potential in the process beyond the laboratory.
