Researchers from the University of Adelaide and the Australian Research Council Centre of Excellence for Carbon Science and Innovation (COE-CSI) have developed two innovative electrolyzer systems that produce hydrogen using urea from wastewater and urine, cutting electricity consumption by up to 27% compared to traditional water electrolysis.
According to lead researcher Professor Shizhang Qiao, the approach offers a cost-effective and sustainable path to green hydrogen while addressing wastewater treatment challenges. The first system uses pure urea in a membrane-free setup with a copper-based catalyst, but relies on energy-intensive industrial urea production via the Haber-Bosch process. To overcome this, the team developed a second system powered by naturally occurring urea in human urine.
Urine, however, contains chloride ions that can trigger unwanted side reactions, generating corrosive chlorine gas. To counter this, the researchers introduced a chloride-mediated oxidation mechanism using a carbon-supported platinum catalyst, improving system durability and hydrogen efficiency. This method achieved an energy consumption as low as 4.05 kWh per cubic meter of hydrogen, outperforming conventional electrolysis.
Importantly, the team’s system brings hydrogen production costs down to $1.81 per kg—lower than both fossil-fuel-based grey hydrogen and the U.S. Department of Energy’s 2030 cost target of $2.00–$2.50. The researchers are now working on replacing platinum with non-precious metals and scaling the system to enable both hydrogen recovery and nitrogen-rich wastewater treatment. The studies were published in Angewandte Chemie International Edition and Nature Communications.
