A recent review article published in Industrial Chemistry & Materials comprehensively investigated chemical-assisted water (H2O) electrolysis as a sustainable and efficient green hydrogen (H2) production method. This approach offers a promising alternative to conventional techniques, addressing the need for cleaner energy sources while reducing carbon dioxide (CO2) emissions. The researchers aimed to enhance H2 generation efficiency and support the transition to sustainable energy through innovative technologies.
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Advancements in H2 Production Technologies
The global dependence on fossil fuels has significantly increased CO2 emissions, highlighting the urgent need for sustainable energy solutions. In response, H2 has emerged as a promising alternative due to its zero-emission combustion and high energy density of 140 MJ kg-1, compared to approximately 50 MJ kg-1 for conventional solid fuels.
Among various H2 production methods, H2O electrolysis is a key technology for generating green H2 without carbon emissions. This process involves splitting H2O molecules into H2 and oxygen (O2) using electricity, primarily through the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER). However, high reaction overpotentials, especially in the OER due to complex pathways, hinder the energy efficiency of the process, necessitating innovative approaches to improve its viability.
Chemical-Assisted Electrolysis: A Novel Approach
In this paper, the authors explored chemical-assisted methods as a new technique to overcome conventional electrolysis limitations by replacing the OER with alternative oxidation reactions. This method enables H2 production at lower voltages while generating byproducts and mitigating pollutants, offering both environmental and economic benefits.
The researchers reviewed various types of chemical-assisted electrolysis, including alcohol, ammonia, urea, hydrazine, and biomass oxidation, each with unique advantages and challenges.
The study detailed advancements in reaction mechanisms and catalyst design aimed at reducing voltage. It also explored catalyst characterization, performance evaluation, and computational modeling methodologies to determine optimal conditions and materials for enhancing production efficiency while minimizing energy consumption.
Findings: Impacts of Implementing Chemical Electrolysis
The outcomes showed that chemical-assisted H2O electrolysis significantly improved H2 production efficiency by lowering the voltage. For example, alcohol oxidation reactions, particularly methanol and ethanol, operated at lower thermodynamic potentials than the OER. Platinum-based catalysts exhibited high current densities and Faradaic efficiencies, though carbon monoxide poisoning and stability issues often hindered their performance.
Ammonia oxidation (AOR) produced nitrogen (N2) as a byproduct and required lower thermodynamic potentials but faced challenges related to catalyst deactivation due to N2 intermediate accumulation. Urea oxidation (UOR) converted urea into N2, CO2, and H2O, though its sluggish kinetics required advanced catalysts. Hydrazine oxidation (HzOR) offered low voltage needs and rapid kinetics, but hydrazine synthesis remained energy-intensive.
Furthermore, biomass oxidation, including glycerol and glucose oxidation, provided economic benefits by generating valuable byproducts alongside H2 production. These results emphasized optimizing catalyst design and reaction conditions to improve selectivity for high-value products while minimizing unwanted byproducts.
Applications of Chemical-Assisted Water Electrolysis
This study has significant implications beyond H2 production, benefiting industries such as wastewater treatment, renewable energy storage, and sustainable chemical manufacturing. Chemical-assisted H2O electrolysis enhances H2 generation while producing valuable byproducts, optimizing industrial processes to reduce carbon footprints and improve economic viability. The authors underscored its relevance in the global transition to cleaner energy, emphasizing the need for efficient and cost-effective H2 production.
This approach also holds promise for renewable energy storage and fuel cells that utilize H2 as a clean energy carrier. Integrating chemical-assisted electrolysis into wastewater treatment could enable resource recovery and pollution mitigation. Overcoming catalyst durability, scalability, and efficiency challenges will be crucial for advancing this technology, strengthening the H2 economy, and supporting global decarbonization efforts.
Conclusion and Future Directions
This review highlighted chemical-assisted H2O electrolysis as a promising alternative to conventional production methods. By addressing the limitations of traditional electrolysis, this innovative approach enhances efficiency and economic viability. The findings emphasize the importance of advancing catalyst design, optimizing reaction conditions, and scaling up these technologies for industrial applications.
As the demand for clean energy grows, chemical-assisted electrolysis could play a key role in the transition toward a sustainable economy. Future work should focus on ensuring long-term stability, achieving high current densities, and improving cost-effectiveness for real-world implementation. Overcoming these challenges could significantly contribute to global decarbonization and support the development of a carbon-neutral energy future.
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Source:
Lee, J., Lee, S, A., & Jang, H, W. Unlocking the potential of chemical-assisted water electrolysis for green hydrogen production. Industrial Chemistry & Materials, 2025. DOI: 10.1039/D4IM00163J, https://pubs.rsc.org/en/content/articlelanding/2025/im/d4im00163j#!recentarticles