In a breakthrough that promises to transform the production of green hydrogen, Australian scientists have developed two highly efficient and economically viable systems capable of generating hydrogen from urea present in human urine or wastewater.
These methods represent an innovative alternative to conventional water electrolysis, which, although clean, requires a high energy demand, making it costly compared to hydrogen obtained from fossil fuels (grey hydrogen).
Lower electricity consumption and non-toxic by-products
The project, led by researchers from the Centre of Excellence for Carbon Science and Innovation and the University of Adelaide, has overcome historical limitations of urea electrolysis:
- Higher efficiency in hydrogen extraction.
- Electricity consumption reduced by 20% to 27% compared to water electrolysis.
- Production of harmless gaseous nitrogen, avoiding the generation of toxic nitrates and nitrites.
These findings, published in Angewandte Chemie International Edition and Nature Communications, demonstrate their viability for industrial applications.
From urine to hydrogen: circular economy in action
The innovation lies not only in process improvement but also in its raw material source. Instead of using pure urea, which requires expensive and polluting industrial synthesis, scientists have tested the use of human urine and wastewater with high nitrogen content.
“If these systems are scaled up, they will not only allow cheaper green hydrogen production but also remediate aquatic environments contaminated with nitrogen”, explained Professor Yun Zheng, one of the lead authors.
Solution to technical barriers: the chlorine challenge
One obstacle in using urine for electrolysis is the presence of chlorides, which can generate corrosive chlorine and damage the system’s anode.
To address this, researchers designed a chlorine-mediated oxidation mechanism with platinum catalysts on carbon supports, stabilizing the process and ensuring its efficiency.
“In the first system, we designed a low-cost membrane-free electrolysis with pure urea. In the second, we used urine and a platinum catalyst to maintain efficiency and prevent corrosion”, detailed Professor Shaobin Qiao.
While the use of platinum is effective, researchers acknowledge that its cost and scarcity make it unsustainable in the long term, so the next step will be to develop catalysts with non-precious metals, further reducing the environmental and economic impact.
An accessible green hydrogen future
This advancement represents a dual environmental solution, combining:
- Clean energy production with green hydrogen.
- Wastewater treatment, reducing contamination from excessive nitrogen.
If industrial scaling is achieved, it could significantly reduce the cost of green hydrogen, accelerate the energy transition, and optimize the management of human and urban waste.
Circular economy in action: from waste to renewable energy
Australian research sets a new course in the development of sustainable technologies, showing how even the most everyday waste can become key resources for a more sustainable planet.
