Producing green hydrogen requires highly active and durable catalysts for the hydrogen evolution reaction (HER) to enhance overall reaction efficiency. High-performance HER has been developed recently, using noble metals such as platinum (Pt), ruthenium (Ru), iridium (Ir), as well as non-noble metals including sulfides, carbides, nitrides, and phosphides.
Let’s look at:
- synthesis strategies
- performance enhancement methods
- the interplay between structure, composition, and catalytic performance
- density functional theory (DFT) calculations to elucidate the mechanisms underlying the improvement of HER performance
- hydrolysis challenges and proposed solutions
Introduction
The urgent global need to transition towards sustainable energy sources has driven significant research efforts towards the development of efficient hydrogen production techniques. Hydrogen, being a clean and versatile energy carrier, holds immense potential to mitigate carbon emissions and meet future energy demands sustainably. Among the various methods of hydrogen production, water electrolysis powered by renewable energy sources such as solar and wind energy stands out for its ability to produce hydrogen with high efficiency and minimal environmental impact.
However, the commercial viability of water electrolysis hinges on the development of highly efficient and durable catalysts, particularly for the hydrogen evolution reaction (HER). The HER is a key step in water electrolysis, where water molecules are split into hydrogen and oxygen gases. To improve the overall efficiency of water electrolysis, it is crucial to enhance the catalytic activity and stability of HER catalysts.
Recent Developments in Electrocatalysts
In recent years, significant progress has been made in the development of electrocatalysts for the HER. Researchers have explored a wide range of materials, including noble metals such as platinum (Pt), ruthenium (Ru), and iridium (Ir), as well as non-noble metals like sulfides, carbides, nitrides, and phosphides. These materials exhibit varying catalytic activities and stabilities, depending on their composition, structure, and synthesis methods.
Synthesis strategies play a crucial role in tailoring the properties of electrocatalysts for the HER. Various methods, such as wet chemical synthesis, electrodeposition, and atomic layer deposition, have been employed to fabricate electrocatalysts with desired morphologies and compositions. Moreover, doping and alloying techniques have been used to enhance the catalytic activity and stability of electrocatalysts.
Density Functional Theory (DFT) Calculations
Density functional theory (DFT) calculations have emerged as powerful tools for understanding the fundamental mechanisms underlying the catalytic activity of electrocatalysts. By simulating the electronic structure and reaction kinetics of catalyst materials, DFT calculations provide valuable insights into the factors governing HER performance. Researchers have employed DFT calculations to elucidate the role of active sites, surface defects, and reaction intermediates in HER catalysis, thereby guiding the design of improved electrocatalysts.
Challenges and Future Perspectives
Despite significant advancements in electrocatalyst development, several challenges remain to be addressed. The high cost and limited availability of noble metals pose barriers to the widespread adoption of HER catalysts. Additionally, the stability of electrocatalysts under harsh operating conditions, such as acidic or alkaline environments, is a major concern.
Future research efforts in the field of electrocatalysis should focus on addressing these challenges and advancing the development of cost-effective and durable HER catalysts. Novel synthesis strategies, such as templating and self-assembly techniques, could lead to the fabrication of electrocatalysts with improved performance and stability. Moreover, the integration of advanced characterisation techniques, such as in situ spectroscopy and microscopy, could provide deeper insights into the reaction mechanisms of electrocatalysts.
In conclusion, electrocatalysts play a crucial role in advancing the field of hydrogen production through water electrolysis. By developing efficient and durable HER catalysts, researchers can contribute to the realisation of a sustainable and carbon-neutral energy future. Further research efforts aimed at understanding the fundamental principles governing electrocatalysis and overcoming existing challenges will pave the way for the widespread adoption of hydrogen as a clean energy carrier.
Source
Recent advances in electrocatalysts for efficient hydrogen evolution reaction, Rare Metals, 2024-05-06
Boˆreal 