A new method quickly extracts 90% of hydrogen from aluminum

A new process could unleash the great potential of hydrogen transportation.

Researchers from UC Santa Cruz developed a new cost-effective method for generating large amounts of hydrogen fuel using the reactivity of aluminum, a press release explains. They hope their process can be scaled up for mass commercial use.

Scientists have long sought to harness the property of aluminum that allows it to strip oxygen from water molecules to generate hydrogen gas. Now, in a new study published in Applied Nano Materials, the team of researchers reveals how they produced a cheap composite of gallium and aluminum to create aluminum nanoparticles that react rapidly with water to produce large amounts of hydrogen.

After the reaction, which according to the researchers "yields 90% of the hydrogen that could theoretically be produced from reaction of all the aluminum in the composite", the gallium can be easily recovered for reuse. "We don't need any energy input, and it bubbles hydrogen like crazy. I've never seen anything like it," said UCSC Chemistry Professor Scott Oliver.

A scalable method for producing vast amounts of hydrogen

The reaction between aluminum and gallium works because gallium removes the aluminum oxide coating that would otherwise form when the material comes in contact with water. When the researchers ran measurements on their experiments, they showed that the formation of aluminum nanoparticles during the reaction accounted for the very high rate of hydrogen production.

So, not only does the gallium dissolve the aluminum oxide, it also separates the aluminum into nanoparticles. "The gallium separates the nanoparticles and keeps them from aggregating into larger particles," Bakthan Singaram, a co-author on the paper, said.
"People have struggled to make aluminum nanoparticles, and here we are producing them under normal atmospheric pressure and room temperature conditions."

The researchers say the composite for their method can be easily made using readily available sources of aluminum, including used foil and cans. While gallium is less abundant and is expensive, the scientists say it is easy to recover and reuse, which should help to make their method scalable for mass use as the world increasingly experiments with new modes of hydrogen transportation. It's a development that could help incentivize companies to develop hydrogen-fueled cars as well as bolster the work of firms like H2 Clipper, which aim to improve air cargo's environmental footprint by changing the public's perception of hydrogen airships as a means for cargo transportation. Commercial implementation isn't a given, but the components are readily available, and the incentive is more urgent than it has ever been.