Green hydrogen is needed as a fuel for the decarbonization of transportation as well as the chemical industry, especially fertilizer production, and for the energy sector. However, the hydrogen production cost currently limits its use on a large scale.
Researchers from Swansea University and Grenoble Alpes University (Université Grenoble Alpes) have joined forces to develop a practical way to produce green hydrogen using sustainable catalysts. This could be a major step towards making green hydrogen production simpler, more affordable, and more scalable, according to researchers.
In their work, the team used natural enzymes – hydrogenases – to generate green hydrogen using sunlight. Hydrogenases are biological catalysts that can reversibly convert protons and electrons into hydrogen at low overpotentials without being based on precious metals.
Unlike synthetic catalysts based on precious metals like platinum, hydrogenases contain only earth-abundant elements such as iron and nickel. However, the researchers say these enzymes are very sensitive and quickly deactivate when exposed to air, making their practical use near impossible.
Now, the team has developed engineered solvents that enable hydrogenases to function in the air. Simply placing hydrogenases in these solvents instead of water makes them more active and more stable so that they can be practically used in the air to generate hydrogen.
“We integrated synthetic nanoparticles with natural enzymes into so-called hybrid materials, which combine the best of both worlds to achieve new, superior functionality. TiO2 nanoparticles are excellent at using sunlight to generate charges, and hydrogenases are extremely efficient in using these charges to generate green hydrogen,” said Dr. Christine Cavazza, senior scientist at CEA Grenoble. “Combining the two, therefore, allows for the efficient generation of green hydrogen from sunlight, something none of the separate components are capable of.”
The research brought together Swansea University’s expertise in photocatalysis, solvent design, and its focus on delivering practical solutions to complex problems and combined this with knowledge of extracting natural enzymes and utilizing them for renewable energy conversion at the Alternative Energies and Atomic Energy Commission (CEA) and Université Grenoble Alpes (UGA).
“This work is an inspiring example of how combining the expertise of multiple partners in an international collaboration can lead to ground-breaking research advances,” said Dr. Alan Le Goff, senior scientist at CNRS Grenoble.
Using sustainable catalysts such as hydrogenases instead of expensive platinum can lower the cost of electrolyzers and fuel cells, making green hydrogen cheaper to produce and use. It also lowers dependence on imports which can be disrupted by external factors.
- Dr. Michael G. Allan, Thomas Pichon, Dr. Jade A. McCune, Dr. Christine Cavazza, Dr. Alan Le Goff, Dr. Moritz F. Kühnel. Augmenting the Performance of Hydrogenase for Aerobic Photocatalytic Hydrogen Evolution via Solvent Tuning. Angewandte Chemie, 2023; DOI: 10.1002/anie.202219176