Producing clean hydrogen energy usually involves the oxygen evolution reaction (OER), which has the unfortunate drawback of being sluggish and inefficient. Catalysts can fast-track this process, but it is no easy task finding the ideal candidate for the job. However, researchers at Tohoku University found that incorporating gadolinium (Gd) into iron (Fe)-doped nickel oxide (NiO) markedly enhances OER activity. In addition, this catalyst is naturally abundant, relatively inexpensive, nontoxic, and stable.
Density functional theory (DFT) calculations were used to provide an in-depth analysis of the reaction mechanisms. They found that Gd-doping improves performance by opening up oxygen vacancies that facilitate the lattice oxygen oxidation mechanism.
Gd-doping reduces the theoretical overpotentials for the Fe and Ni sites, which improves performance. The overpotential was 40mV lower than Fe-doped NiO (without Gd). It also demonstrates favourable kinematics (Tafel slope: 43.1 mV dec -1 ). In addition, Gd and Fe co-doped NiO exhibits remarkable long-term stability exceeding 150 hours and robust performance in an anion exchange membrane water electrolysis system, operating continuously for over 120 hours.
"This research plays a crucial role in advancing green energy solutions by improving water electrolysis, a key technology for producing green hydrogen from renewable sources like wind and solar power," says Hao Li, associate professor at Tohoku University's Advanced Institute for Materials Research (WPI-AIMR).
Green hydrogen is essential for clean energy systems, with applications in fuel cell vehicles, industrial processes, and other energy-intensive sectors. By enhancing electrolysis efficiency, this study supports large-scale hydrogen production - thus reducing our reliance on fossil fuels and lowering greenhouse gas emissions.
"We plan to scale up the synthesis process to ensure consistent production for industrial applications, and conduct extended stability tests under realistic conditions," says Li.
Key experimental data and computational structures from this study are available in the Digital Catalysis Platform ( DigCat ), the largest catalysis database developed by the Hao Li Lab.
The findings were published in Advanced Functional Materials on February 26, 2025. The article processing charge (APC) was supported by the Tohoku University Support Program.
About the World Premier International Research Center Initiative (WPI)
The WPI program was launched in 2007 by Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) to foster globally visible research centers boasting the highest standards and outstanding research environments. Numbering more than a dozen and operating at institutions throughout the country, these centers are given a high degree of autonomy, allowing them to engage in innovative modes of management and research. The program is administered by the Japan Society for the Promotion of Science (JSPS).
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Advanced Institute for Materials Research (AIMR)
Tohoku University
Establishing a World-Leading Research Center for Materials Science
AIMR aims to contribute to society through its actions as a world-leading research center for materials science and push the boundaries of research frontiers. To this end, the institute gathers excellent researchers in the fields of physics, chemistry, materials science, engineering, and mathematics and provides a world-class research environment.
AIMR site: https://www.wpi-aimr.tohoku.ac.jp/en/
Advanced Functional Materials
Gd-Induced Oxygen Vacancy Creation Activates Lattice Oxygen Oxidation for Water Electrolysis
26-Feb-2025