The researchers at IIT and BeDimensional used nanoparticles of ruthenium, a type of ruthenium that chemically behaves similarly to platinum but is much cheaper, as the active phase of the electrolyzer cathode, thus improving the efficiency of the entire electrolyzer. **iit-istituto italiano di tecnologia
How can green hydrogen be produced more efficiently and cheaply?Obviously, small ruthenium particles and solar systems for water electrolysis. This is managed by the Italian Polytechnic Institute of Genoa (IIT) and Bedimensional Sp.a.(IIT's spin-offs) to come up with a solution.
The technology, developed in the context of joint laboratory activities and recently published in Nature Communications and the Journal of the American Chemical Society, is based on a series of new electrocatalysts that can reduce the cost of green hydrogen production on an industrial scale.
Hydrogen is considered a sustainable energy carrier and an alternative to fossil fuels. However, not all hydrogen is created equal when it comes to environmental impact. In fact, the main way hydrogen is produced today is through methane steam reforming, a fossil fuel-based release of carbon dioxide (CO2) as a by-product. The hydrogen produced by this process is classified as either "gray" (when CO2 is released into the atmosphere) or "blue" (when CO2 is captured and geologically sequestered).
In order to drastically reduce emissions to zero by 2050, these processes must be replaced by more environmentally sustainable processes that provide "green" (i.e., net-zero emissions) hydrogen. The cost of "green" hydrogen largely depends on the energy efficiency of the device (electrolyzer) that splits water molecules into hydrogen and oxygen.
Researchers from the joint team of this discovery have developed a new method that guarantees higher efficiency than currently known methods in converting electrical energy (for the energy bias of water molecules) into chemical energy stored in the resulting hydrogen molecules. The team developed the concept of a catalyst and used renewable energy sources, such as electricity generated by solar panels.
In our research, we've shown how to maximize the efficiency of a robust, well-established technology, albeit with an initial investment that is slightly higher than what is required for a standard electrolyzer. This is because we are using ruthenium and other *** said Yong Zuo and Michele Ferri from the Genoa IIT Nanochemistry Group.
The researchers used nanoparticles of ruthenium, a type of ruthenium that chemically behaves similarly to platinum, but is much cheaper. Ruthenium nanoparticles are used as the active phase of the electrolyzer cathode, thereby increasing the efficiency of the entire electrolyzer.
We performed electrochemical analyses and tests under conditions of industrial significance, allowing us to evaluate the catalytic activity of the material. In addition, theoretical simulations allow us to understand the catalytic behavior of ruthenium nanoparticles at the molecular level;In other words, the mechanism of water on its surface," explains Sebastiano Bellani and Marile Na Zappia, who participated in the discovery.
Combining our experimental data with other process parameters, we carried out a techno-economic analysis that demonstrated the competitiveness of the technology compared to state-of-the-art electrolyzers. ”
Ruthenium is a *** obtained in small quantities as a by-product of platinum extraction (30 tonnes per year compared to 200 tonnes per year for platinum), but at a lower cost (18 tonnes per gram).$5 compared to $30 for platinum). This new technology involves the use of only 40 milligrams of ruthenium per kilowatt, which is very different from the heavy use of platinum (up to 1 gram per kilowatt) and iridium (1 to 2 per kilowatt).5 grams, iridium ** is about $150 per gram) in stark contrast to the characteristics of proton exchange membrane electrolyzers.
By using ruthenium, researchers at IIT and BeDimension have improved the efficiency of alkaline electrolyzers, a technology that has been used for decades due to its robustness and durability.
For example, this technology was on the Apollo 11 capsule, which sent humans to the moon in 1969. The new ruthenium-based cathode series for alkaline electrolyzers that has been developed is highly efficient and has a long service life, thus reducing the production costs of green hydrogen.
"In the future, we plan to apply this and other technologies, such as nanostructured catalysts based on sustainable two-dimensional materials, to large-scale electrolyzers powered by renewable energy, including electricity generated by photovoltaic panels," the researchers concluded.
More information: Yong Zuo et al., Ru-Cu nanoheterostructures for efficient hydrogen evolution reactions in alkaline water electrolyzers, Journal of the American Chemical Society (2023). doi： 10.1021/jacs.3c06726