Researchers engineered a graphene-encased catalyst with ultra-low platinum use that delivers high-efficiency, industrial-scale hydrogen production.
Proton exchange membrane (PEM) water electrolysis plays a key role in the production of green hydrogen on a large scale. One of the most commonly used materials in this process is Platinum on Carbon (Pt/C), which serves as an advanced cathode catalyst. Its popularity comes from its ability to effectively bind hydrogen and its strong resistance to acidic environments. However, using high amounts of platinum makes this approach expensive and limits its broader adoption.
In research published in Joule, a team led by Prof. Dehui Deng and Prof. Liang Yu from the Dalian Institute of Chemical Physics (DICP) at the Chinese Academy of Sciences (CAS) worked with Prof. Junling Lu from the University of Science and Technology of China (also part of CAS) and Prof. Hongmei Yu from DICP. Together, they developed a new catalyst that is both highly efficient and stable for use in acidic hydrogen production.
Their innovation centers around a unique “chainmail” catalyst made from a cobalt-nickel (CoNi) nano-alloy that is enclosed within a single layer of graphene. The team found that electrons transferred from the CoNi alloy into the surrounding carbon layer. This process, combined with a 3d-2p electronic interaction, caused the surface of the graphene to accumulate an uneven distribution of π electronic states, which played a critical role in enhancing catalytic behavior.
Synergistic Confinement and Platinum Stability
After depositing Pt single atoms using atomic layer deposition, these enriched asymmetric π electrons exhibited a unique confinement effect on the Pt atoms.
This confinement operated through two synergistic mechanisms. Electron transfer from CoNi to Pt via the graphene layer resulted in an electron-rich Pt site, optimizing hydrogen adsorption energy and promoting hydrogen desorption, thereby improving catalytic activity. Besides, strong interactions between the asymmetric π electrons and the Pt 5d orbital enhanced the structural stability of Pt sites, boosting the durability of the catalyst.
The researchers assembled a PEM water electrolyzer using this catalyst, which achieved an ultra-high current density of 4.0 A cm−2 at 2.02 V and maintained excellent durability over 1,000 hours at 2 A cm−2, using only 1.2 μgPt cm−2 Pt loading. They also assembled a 2.85 kW PEM water electrolyzer using this catalyst, which operated stably for over 300 hours at an industrial current density of 1.5 A cm−2, highlighting its outstanding industrial application potential.
“This work provides a new idea for developing high-performance, long-life, and low-cost catalysts for hydrogen production via acid water electrolysis,” said Prof. Deng.
Reference: “Enriched asymmetric π electrons confining single-site Pt for acidic hydrogen evolution” by Mingxia Xu, Yiran Kang, Leilei Wang, Yunlong Zhang, Guang Jiang, Yafeng Cai, Yunchuan Tu, Qiao Zhao, Jun Chi, Wei Song, Hongmei Yu, Jingting Hu, Wei Liu, Rui Huang, Liang Yu, Junling Lu, Xinhe Bao and Dehui Deng, 28 May 2025, Joule.
DOI: 10.1016/j.joule.2025.101968
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