Opportunity
The electrochemical splitting of water to produce hydrogen is widely recognized as an ideal strategy to reduce reliance on traditional fossil fuels and contribute to carbon neutrality. The hydrogen evolution reaction (HER) is a key process in this context. Currently, commercial HER catalysts for water splitting are based on platinum nanoparticles dispersed on carbon substrates, such as 20% Pt/C. However, the manufacturing methods for commercial Pt/C are complex and costly. Although existing Pt/C catalysts meet basic HER performance requirements, there is a pressing need to develop new catalysts with lower overpotentials, higher electrical conductivity, and improved stability to further reduce energy consumption. Additionally, while crystal-amorphous ultra-nano dual-phase (SNDP) materials show promise as alternatives due to their synergistic effects and large active catalytic interfaces, their development faces limitations. The range of accessible element types in SNDP structures is restricted, and precise control over their composition remains challenging. A significant hurdle is the role of oxygen: although oxygen is essential in many materials, its direct coordination with active sites during HER can be detrimental. Thus, leveraging oxygen to fine-tune electronic structures and enhance HER performance presents a major opportunity for advancing electrocatalyst design.
Technology
This invention addresses the above challenges by introducing a novel oxygen-dominated ultra-nano dual-phase (SNDP) catalytic reaction material on a substrate. The material features an intrinsic crystal-amorphous dual-phase structure, comprising a uniform oxygen-rich amorphous shell encapsulating a core. The core is typically made of transition metals (e.g., palladium, platinum, iridium) or non-precious metals (e.g., vanadium, molybdenum, tungsten), while the shell is formed from high-entropy amorphous alloys (HEAAs) such as Al₀.₅ZnTiZrSiCuNi or FeCoNiMoPB. The SNDP structure is synthesized via industrial magnetron co-sputtering of crystalline metal targets and HEAA targets onto substrates like carbon cloth or nickel foam, with oxygen introduced during the sputtering process. By adjusting oxygen flow rates (0.01–50 sccm), the composition of the SNDP structure can be precisely controlled over a wide range. For example, an optimized SNDP-Pd@HEAA material contains 25.12 at% Pd and 42.24 at% O, with a core diameter of 1–10 nm and a shell thickness of 1–5 nm. This configuration creates abundant active sites with sub-nearest-neighbor oxygen coordination at the crystal-amorphous interfaces, which optimizes the Gibbs free energy for hydrogen adsorption (ΔG_H), enhances water adsorption, and facilitates proton adsorption/desorption. As a result, the material achieves an exceptionally low overpotential of 10.16 mV at 10 mA cm⁻² in alkaline conditions, surpassing commercial 20% Pt/C (34.01 mV). The technology also enables scalable production through room-temperature magnetron sputtering, offering a practical pathway for industrial application.
Advantages
- Achieves a lower overpotential (10.16 mV at 10 mA cm⁻²) compared to commercial 20% Pt/C (34.01 mV), enhancing energy efficiency.
- Exhibits superior stability, maintaining performance over 100 hours at 20 mA cm⁻² in three-electrode systems and 1000 hours at 500 mA cm⁻² in flow-type membrane exchange assembly alkaline water electrocatalytic cells.
- Allows precise tuning of SNDP composition across a broad range by varying oxygen content, overcoming limitations in diversity and adjustability of conventional SNDP structures.
- Utilizes room-temperature industrial magnetron sputtering, enabling scalable and cost-effective mass production.
- Features a high electrochemical active surface area (126.7 mF cm⁻²), approximately 2.75 times that of commercial 20% Pt/C, due to its smooth, uniform morphology.
- Incorporates sub-nearest-neighbor oxygen coordination at interfaces, optimizing electronic structure and catalytic activity without direct oxidation of active metal sites.
Applications
- As electrodes for water splitting, including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrodes.
- In proton exchange membrane fuel cells for enhanced hydrogen production efficiency.
- For metal-air batteries, improving catalytic performance in oxygen reduction reactions.
- In carbon dioxide reduction reactions, leveraging tunable catalytic interfaces.
- As durable catalytic materials in alkaline electrolyzers for industrial hydrogen generation.
- For research and development of next-generation electrocatalysts with tailored electronic properties.
