Advancements in High-Performance Proton Exchange Membranes Enhance Electrochemical LOHC Hydrogen Storage

A groundbreaking advancement in the field of proton exchange membranes (PEMs) has emerged from a collaborative research initiative between Dr. Soonyong So from the Korea Research Institute of Chemical Technology (KRICT) and Professor Sang-Young Lee from Yonsei University. This new membrane technology, designed to optimize electrochemical hydrogen storage systems, utilizes a hydrocarbon-based polymer known as sulfonated poly(arylene ether sulfone) or SPAES. The SPAES membrane boasts an impressive performance enhancement when compared to traditional membranes like Nafion, a commonly utilized perfluorinated PEM.

One of the significant innovations introduced with the SPAES membrane is its ability to drastically reduce toluene permeability. This is particularly critical, as liquid organic hydrogen carriers (LOHCs) such as toluene are increasingly recognized as viable mediums for safely storing and transporting hydrogen. Conventional methods of hydrogen storage, which involve high pressures of over 100 bar or extreme low temperatures of -252.9 °C, pose several handling and safety challenges. In contrast, LOHCs provide a much more manageable alternative since they can be stored and transported under milder conditions.

However, the use of LOHCs presents challenges, particularly regarding the unwanted crossover of toluene molecules through the membrane in electrochemical hydrogenation systems. This crossover significantly undermines operational efficiency. Moreover, it has the potential to contaminate the oxygen evolution reaction (OER) catalyst present on the anode side, which can lead to detrimental impacts on the overall system performance. Addressing this issue was crucial for the success of the new membrane technology.

In their research, the team at KRICT developed the new SPAES membrane with particularly narrow hydrophilic domains, measuring approximately 2.1 nm in width. These channels serve as dedicated proton pathways within the membrane and are designed to reduce toluene permeability significantly. The innovative structure of the SPAES membrane facilitates the exclusion of toluene while promoting efficient proton transport, which is critical for achieving high performance in electrochemical processes. The outcome is a remarkable reduction in toluene crossover, decreased by more than 60% when compared to Nafion.

Moreover, the introduction of the SPAES membrane led to a considerable increase in the Faradaic efficiency of the hydrogenation process, raising it from 68.4% with Nafion to an impressive 72.8% with the new membrane. This enhanced efficiency represents a major leap forward in the functionality of PEMs, setting the stage for improved performance of hydrogen storage systems. Additionally, during long-term operational tests lasting 48 hours, the voltage degradation rate was also reduced significantly by 40%, demonstrating not only the enhanced performance but also the robust stability of the SPAES membrane over extended use.

The potential applications for this revolutionary technology extend far beyond academic curiosity, as the researchers envision its integration into practical setups for hydrogen storage and energy production. They foresee standalone, high-efficiency electrochemical hydrogen storage systems reaching commercialization by 2030. This advancement could lead to substantial developments in eco-friendly energy solutions, particularly relevant for hydrogen fuel cell vehicles and hydrogen power generation initiatives.

KRICT’s President, Youngkook Lee, expressed optimism regarding the widespread applicability of the SPAES membrane technology within the realm of sustainable energy systems. He noted that this innovation could significantly contribute to the hydrogen economy and help overcome existing performance bottlenecks associated with membrane technologies currently in use for electrochemical hydrogen storage applications.

The collaborative research led by Dr. So and Professor Lee also aligns with KRICT’s dedication to advancing chemical technologies for broader societal benefits. As an institute founded in 1976, KRICT has been at the forefront of research in various scientific fields, including chemistry, material science, and environmental science. Their ongoing commitment emphasizes the importance of developing solutions that address critical global challenges related to energy production and sustainability, an imperative that continues to gain urgency in today’s world.

The findings from this research were published in the highly-regarded Journal of Materials Chemistry A, which boasts an impressive impact factor of 10.7. The publication marks a significant milestone in the academic discourse surrounding membrane technology and highlights the promising future of electrochemical hydrogen storage systems fueled by innovative research and development.

This critical work in membrane technology represents a strategic alignment of fundamental research and applied science, demonstrating that advancements in materials science can lead to practical solutions that bolster the transition to a hydrogen-powered future. It is a clear testament to the potential of scientific research to drive progress in energy technologies, harboring hope for sustainable energy solutions that will play a crucial role in achieving global climate goals.

Through continuous research and collaboration, such innovations pave the way for not just technical progress but also for broader systemic changes in how society approaches energy use and sustainability. Ultimately, the development of more efficient, cost-effective, and stable hydrogen storage systems is poised to catalyze the next phase of the energy transition, moving toward a cleaner, more efficient, and environmentally conscious future.

Subject of Research: Development of a new proton exchange membrane (PEM) for electrochemical hydrogen storage systems
Article Title: An efficient toluene barrier membrane for high-performance direct toluene hydrogenation via an electrochemical process
News Publication Date: February 14, 2025
Web References: http://dx.doi.org/10.1039/D4TA06773H
References: Journal of Materials Chemistry A (IF 10.7)
Image Credits: Korea Research Institute of Chemical Technology (KRICT)

Keywords

Proton exchange membranes, electrochemical hydrogen storage, sulfonated poly(arylene ether sulfone), SPAES membrane, liquid organic hydrogen carriers, Faradaic efficiency, hydrogen economy, KRICT, sustainable energy solutions.