Scientists find cheaper way to make hydrogen energy out of water

After a group of scientists led by UNSW showed how to produce the hydrogen needed to power hydrogen-powered automobiles far more cheaply and sustainably, the technology may soon be more than just a curiosity.

Scientists from UNSW Sydney, Griffith University, and Swinburne University of Technology demonstrated in a recent study published in Nature Communications that low-cost metals like iron and nickel can be used as catalysts to speed up this chemical reaction and use less energy to capture hydrogen by splitting it from oxygen in water.

The abundant metals iron and nickel would take the place of the precious metals ruthenium, platinum, and iridium, which are now thought to be standard catalysts in the "water-splitting" process.

The process of water splitting, according to Professor Chuan Zhao of the UNSW School of Chemistry, involves applying an electric charge to water through two electrodes, allowing hydrogen to be separated from oxygen and utilized as fuel for a fuel cell.

"We apply our catalyst to the electrodes in order to lower energy consumption," he explains. The atomic meeting point of iron and nickel on this catalyst is a small nanoscale interface that serves as an active site for water splitting. Here, oxygen may be discharged as a waste that is benign to the environment and hydrogen can be separated from it and recovered for use as fuel."

A record-high efficiency nickel-iron electrode for oxygen production was created in 2015 by Prof. Zhao's group. Prof. Zhao notes that iron and nickel by themselves are not effective catalysts for the production of hydrogen, but that their combination at the nanoscale is "where the magic happens."

"These materials' properties are fundamentally changed by the nanoscale interface," he claims. According to our findings, the nickel-iron catalyst for hydrogen production can be just as active as the platinum one.

In addition, by employing components that are readily available on Earth, we might reduce not just the cost of production by employing one catalyst rather than two, but also the cost of creating both hydrogen and oxygen through the use of our nickel-iron electrode.

A cursory look at the current metal prices demonstrates why this could be the catalyst required to accelerate the shift to the so-called hydrogen economy. Priced per kilogram, iron is $0.13 while nickel is $19.65. In comparison, the prices of ruthenium, platinum, and iridium are $11.77, $42.13, and $69.58 per gram, respectively—a significant price difference of thousands of times.

Prof. Zhao states, "We currently have this huge incentive to move from our fossil fuel economy to a hydrogen economy so that we can be using hydrogen as a clean energy carrier which is abundant on Earth."

"The hydrogen economy has been discussed for a long time, but it appears to be here to stay this time."

According to Prof. Zhao, if the technology for water-splitting is further improved, hydrogen fuelling stations like to gas stations may exist in the future, where you could fill up your hydrogen fuel-cell vehicle with hydrogen gas created by this water-splitting reaction. If an electric automobile powered by lithium batteries were to be refueled, it might be completed in a matter of minutes as opposed to hours.

"We hope that stations like these will be able to use our research to produce their own hydrogen with inexpensive, effective catalysts and sustainable sources like solar and water."