QUT scientists have found a way to use iron ore as an efficient catalyst for the production of hydrogen from water by electrolysis.
Hydrogen is seen as a major future energy source, with the potential to provide power for transportation through hydrogen fuel cells and to act as an energy storage medium for electricity grids.
The findings are particularly significant because Australia is positioning itself as a major supplier of hydrogen for renewable energy purposes and is also one of the world’s largest iron ore producers.
The research, Conversion of Iron Ore into an Active Catalyst for the Oxygen Evolution Reaction, was authored by Associate Professor Anthony O’Mullane, Mohammed Abu Sayeed and Joseph Fernando. It has been published in the journal Advanced Sustainable Systems(subscription required to view full article).
Electrolysis is the process of using electricity to separate water into hydrogen and oxygen and is one of the most promising methods of producing high purity hydrogen. Renewable energy from solar or wind can be used to power the electrochemical reaction, which would result in a sustainable, zero-emissions energy cycle.
Associate Professor Anthony O’Mullane, from QUT’s Science and Engineering Faculty and the Institute for Future Environments, said several factors had prevented the successful implementation of water electrolysis on a large or industrial scale.
“The oxygen producing reaction at the anode can be slow and inefficient, and the electrocatalysts currently used are based on very expensive materials such as ruthenium and iridium.
“Oxides of other materials such as manganese, iron, cobalt and nickel have been studied as oxygen evolution reaction (OER) electrocatalysts, but making them often requires high temperatures, high pressures, an inert atmosphere or highly pure reagents which increases production costs,” he said.
“Our research has found that using iron ore coated with a nickel oxyhydroxide layer produces a highly active OER electrocatalyst.”
Iron ore generally consists of hematite, magnetite and goethite and is used as the raw material for making pig iron prior to the production of steel.
“In its raw state iron ore is electrically insulating, but we found that adding a coating of nickel hydroxide through an electrochemical process transforms it into a catalyst that gives high OER activity for up to 20 hours of electrolysis with good stability,” Associate Professor O’Mullane said.
“This research has shown that it is possible to convert iron ore into a very efficient catalyst for water electrolysis, and therefore has excellent potential to scale up to industrial volumes as the nickel oxyhydroxide coating process is relatively simple.
“With Australia having some of the world’s largest iron ore reserves, there’s great potential to value-add to this resource rather than simply exporting it in its raw state.”