Journal: Applied Catalysis B: Environmental
Year: 2022
Citations: 285
DOI: 10.26599/NRE.2022.9120028

Abstract

Electrochemical seawater splitting represents a promising approach for sustainable hydrogen production, but the harsh seawater environment poses significant challenges for catalyst stability and selectivity. The oxygen evolution reaction (OER) in seawater is complicated by competing chlorine evolution reaction (CER) and catalyst corrosion. Here, we report benzoate anions-intercalated NiFe-layered double hydroxide (NiFe-LDH) nanosheet arrays with enhanced stability for electrochemical seawater oxidation. The benzoate intercalation modifies the electronic structure and surface properties of NiFe-LDH, improving both catalytic activity and stability in seawater electrolysis. The catalyst demonstrates excellent performance with high selectivity for oxygen evolution over chlorine evolution and remarkable stability over extended operation periods.

Summary

This innovative materials science research addresses critical challenges in sustainable hydrogen production through electrochemical seawater splitting, focusing on developing catalysts that can operate effectively in harsh marine environments. The study tackles the significant technical hurdles posed by seawater’s corrosive nature and the competing chemical reactions that occur during electrolysis, particularly the unwanted chlorine evolution reaction that competes with desired oxygen evolution. The research presents a novel approach using benzoate anions-intercalated nickel-iron layered double hydroxide nanosheet arrays to enhance both catalytic performance and long-term stability.

The key innovation lies in the strategic intercalation of benzoate anions into the layered double hydroxide structure, which fundamentally modifies the electronic structure and surface properties of the catalyst material. This modification enhances both catalytic activity for the desired oxygen evolution reaction and selectivity against the competing chlorine evolution reaction, while simultaneously improving the catalyst’s resistance to corrosion in the harsh seawater environment. The nanosheet array architecture provides high surface area and efficient mass transport, optimizing the catalyst’s performance for practical applications.

The research demonstrates excellent practical performance with high selectivity for oxygen evolution over chlorine evolution and remarkable stability during extended operation periods, addressing key requirements for commercial seawater electrolysis applications. This work contributes significantly to the development of sustainable hydrogen production technologies that could utilize abundant seawater resources rather than competing with freshwater supplies. The enhanced stability and selectivity achieved through this materials engineering approach represents an important step toward making seawater electrolysis economically viable for large-scale hydrogen production.

Main Takeaways

• Seawater Electrolysis Innovation: The research addresses critical challenges in sustainable hydrogen production by developing catalysts specifically designed for harsh seawater environments, potentially utilizing abundant ocean resources.

• Enhanced Selectivity Control: The benzoate intercalation strategy successfully improves selectivity for oxygen evolution over competing chlorine evolution reaction, addressing a major technical barrier in seawater electrolysis.

• Superior Stability Performance: The modified catalyst demonstrates remarkable stability during extended operation periods, overcoming the corrosion and degradation issues that typically plague seawater electrolysis systems.

• Advanced Materials Engineering: The strategic intercalation of benzoate anions modifies electronic structure and surface properties, simultaneously enhancing catalytic activity, selectivity, and stability.

• Practical Application Potential: The excellent performance characteristics make seawater electrolysis more economically viable for large-scale hydrogen production, particularly in coastal regions with abundant renewable energy.

• Sustainable Energy Contribution: The technology enables hydrogen production without competing with freshwater resources, supporting sustainable energy development and clean fuel production from abundant seawater.