Related Experiment Video
Updated: Jan 16, 2026
10:15
Solar-Driven Electrochemical Green Fuel Production from CO2 and Water Using Ti3C2Tx MXene-Supported CuZn and NiCo Catalysts
Published on: November 7, 2025
470
A reversible alkaline water electrolyser for load-flexible power-H2 interconversion enabled by bifunctional catalyst.
Xiaoyu Yan1,2, Yang Zhao1, Le Ke1,2
1Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
National Science Review
|September 29, 2025
Summary
A novel membrane-free alkaline water electrolyzer utilizes a NiOOH redox mediator for efficient hydrogen production and reversible fuel cell operation. This system offers grid-scale energy storage solutions with high purity hydrogen and excellent load flexibility.
Area of Science:
- Electrochemistry
- Energy Storage
- Renewable Energy Integration
Background:
- Grid-scale energy storage is crucial for integrating renewable energy sources.
- Conventional alkaline water electrolyzers and membrane-based fuel cells have limitations in cost and efficiency.
- Hydrogen is an ideal energy carrier for storing and converting renewable energy.
Purpose of the Study:
- To develop a safe, efficient, and affordable electrochemical energy storage system.
- To create a membrane-free alkaline water electrolyzer for reversible power-to-hydrogen conversion.
- To overcome the limitations of conventional electrolyzers and fuel cells.
Main Methods:
- Development of a single-compartment, membrane-free alkaline water electrolyzer.
- Utilizing a NiOOH redox mediator between two bifunctional electrodes.
- Implementing decoupled anodic and cathodic reactions for gas separation.
Main Results:
- High-purity hydrogen (>99%) produced at diverse current densities (>500 mA cm⁻² and <50 mA cm⁻²), demonstrating load flexibility.
- Successful reversible operation as a fuel cell with a peak power density of 0.23 W cm⁻².
- Functionality as a Ni-H₂ battery with a peak power density of 1.4 W cm⁻² and 83.6% round-trip efficiency.
- Stable performance over a 350-hour endurance test with easy switching between operational modes.
Conclusions:
- The developed membrane-free electrolyzer offers a promising solution for grid-scale energy storage.
- It provides efficient hydrogen production, reversible fuel cell operation, and battery functionality.
- This technology enhances the integration of renewable energy with improved safety and affordability.
Related Concept Videos
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.8K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.8K
02:13Reduction of Alkenes: Catalytic Hydrogenation
13.9K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
13.9K
03:12Batteries and Fuel Cells
30.7K
A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...
30.7K
03:00Electrolysis
30.2K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
30.2K
01:17Ion Exchange
1.1K
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
1.1K
02:45Acid-Catalyzed Hydration of Alkenes
17.0K
Alkenes react with water in the presence of an acid to form an alcohol. In the absence of acid, hydration of alkenes does not occur at a significant rate, and the acid is not consumed in the reaction. Therefore, alkene hydration is an acid-catalyzed reaction.
17.0K