A group of Queensland researchers have used mining waste to make a catalyst that could render hydrogen fuel production cheaper and more efficient.
Hydrogen gas, which can be made by electrolysing water, should be a critical clean fuel by mid-century. The electrolysis process needs metals to catalyse it – and generally, expensive precious metals do a better job as catalysts.
A paperpublishedinAdvanced Energy & Sustainability Researchdescribes a cheaper type of hydrogen catalyst. These catalysts are made mostly from feldspars: aluminosilicate rocks which make up a large proportion of the Earth’s crust, and thus often turn up in mining waste. The feldspars are coated with a few nanometres of nickel, cobalt or iron.
“Water splitting involves two chemical reactions – one with the hydrogen atom and one with the oxygen atom – to cause them to separate,” explains Professor Ziqi Sun, a researcher at Queensland University of Technology and co-author on the paper.
“This new nano-coated material triggered the oxygen evolution reaction, which controls the overall efficiency of the whole water-splitting process.”
Read more:A new carbon capture catalyst
The cobalt-covered feldspar was the most effective of the catalysts, rivalling much pricier commercial ruthenium catalysts in efficiency.
Sun says the catalysts could also be used in lithium-ion batteries and other electrochemical processes, giving it further renewable energy applications.
The catalyst is ready for pilot testing, and the researchers say it would be a simple thing to scale up.
“铝矽酸盐通常但书d in various mining tailings and is so cheap that mining companies would normally pay to dispose of it,” says Dr Hong Peng, a researcher at the University of Queensland and co-author on the paper.
“Australia’s abundance of aluminosilicate and the simplicity of this modification process should make industrial scale production of this new catalyst easy to achieve,” says Sun.