Aluminum: A Sustainable Solution for Hydrogen Fuel?

Scientists Develop Aluminum-Based Catalyst to Promote Efficiency in Hydrogen Production

Researchers from POSTECH and Sogang University working to develop a novel technology used aluminum (Al) for improved performance of the catalyst in water electrolysis for the production of hydrogen. The novel approach overcomes the shortcomings of current catalyst technology, making the process more efficient and stable on a large-scale production of hydrogen.

Improving Hydrogen Production Technology
Hydrogen is also becoming increasingly popular as a clean source of energy to substitute for fossil fuels. Among the most studied processes for the production of hydrogen is alkaline water electrolysis, and one of them is alkaline water electrolysis in which an alkaline solution is used as an electrolyte. The process is found to be economically feasible and can be applied for large-scale hydrogen production.

Water electrolysis relies on the catalysts that facilitate two major reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). HER involves the production of hydrogen gas (H₂) from hydrogens ions (H⁺) and electrons, whereas OER generates oxygen gas (O₂) by the oxidation of hydroxyl ions (OH⁻).

Nickel-iron (Ni-Fe) catalysts are frequently applied to the OER process but are of low stability and activity, and hence cannot be commercialized. All these shortcomings were overcome by the scientists through the incorporation of aluminum into the catalyst, which greatly enhanced its stability and efficiency.

Role of Aluminum in Enhancing Catalyst Efficiency
Aluminum is also generally found to be prone to corrosion in an alkaline environment. The researchers, nonetheless, engineered the material in such a way that the material would remain stable in form at the surface of the electrode to avert corrosion without sacrificing control over the electron catalytic structure. The new structure triggered the oxygen-generating reaction that was responsible for the improvement in overall efficiency of the catalyst.

In tests of an electrolysis cell under laboratory experiments, a newly prepared Ni-Fe-Al catalyst was found to be around 50% more effective than existing catalysts. The catalyst showed high current density even at low voltages, which were energy-efficient. Steady-state operation over extended periods also proved its feasibility for scale-up hydrogen production.

Potential Impact on the Hydrogen Economy
This study is a technological innovation in the production of hydrogen. Aluminum was the substance used, and scientists avoided the shortcomings of previous nickel-iron catalysts while increasing the electrolysis process to make it economical and efficient. This new technology can speed up the development of hydrogen energy as a source of power as opposed to fossil fuels.

The research was jointly done by POSTECH researcher Dr. Yong-Tae Kim, Dr. Sang-Moon Jung, and Ph.D. student Byeong-Jo Lee and Sogang University researchers directed by Professor Seoin Back. The paper appears in ACS Catalysis, the American Chemical Society's peer-reviewed journal.

Funding and Support
This research was funded by the National Research Foundation of Korea, the Ministry of Science and ICT, and the Ministry of Trade, Industry, and Energy.