Researchers led by Andreas Stirl at Deutsches Elektronen-Synchrotron (DESY) have laid the groundwork for an alternative hydrogen storage method, Utilization A network of palladium nanoclusters with iridium seeds with a cluster diameter of 1.2 nm. The team, which also includes researchers from the Universities of Cologne and Hamburg, published their findings in the journal ACS nano.
The fact that palladium can absorb hydrogen like a sponge has been known for a long time.
However, so far getting the hydrogen out of the substance has been a problem again. That’s why we tried palladium particles that are only about a nanometer in diameter.
– Andreas Stirl
To ensure that the fine particles are durable enough, they are held in place by a core made of the rare precious metal iridium. Moreover, they are attached to the graphene backing.
The palladium nanoparticles (green) are stabilized by an iridium core (red). Hydrogen can accumulate on the surface and can be released again by heating. Credit: DESY, Andreas Stirl
Binding of palladium particles to graphene at intervals of just 2.5 nanometers results in a regular periodic structure, said Stierle, president of DESY NanoLab.
The PETRA III DESY X-ray source was used to observe what happens when palladium particles come into contact with hydrogen: Basically, the hydrogen sticks to the surface of the nanoparticles, and almost nothing penetrates inside.
All it takes to recover the stored hydrogen is to add a little heat; Hydrogen is rapidly released from the surface of the particles, because the gas particles do not have to escape from the interior of the block.
The researchers wanted to find out what storage densities the new method could achieve, Stirl said. There is still a need to overcome challenges before starting practical application. For example, another form of carrier carbon structure may be more suitable than graphene—the researchers are considering using carbon sponges, which have small pores. A large number of palladium nanoparticles must fit inside these particles.
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Franz, U. Schroeder, R.; Sheddock, B. Arendt, H. No, F.; Funk, T.; Micheli, A.; Stirl (2021) “Hydrogen solubility and atomic structure of graphene-supported nanoclusters”, ACS nano dui: 10.1021 / acsnano.1c01997
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