New nanomaterials developed by the United States can efficiently extract hydrogen gas from alcohols

2024-03-05

Hydrogen is a sustainable clean energy source that does not emit toxic gases and can add value to multiple industries such as transportation, power generation, and metal manufacturing. The technology for storing and transporting hydrogen has bridged the gap between sustainable energy production and fuel use. More efficient hydrogen delivery systems can bring many benefits to applications such as fixed power sources, mobile power sources, and mobile vehicles, making them an indispensable part of the hydrogen economy. However, traditional hydrogen storage and transportation technologies are very expensive and can easily contaminate hydrogen. Therefore, researchers have been searching for reliable, low-cost, and simple alternative technologies.

According to foreign media reports, a team of researchers at the Lawrence Berkeley National Laboratory in the United States has designed and synthesized an efficient material that can accelerate the extraction of hydrogen from alcohols. This material is a catalyst composed of tiny nickel metal clusters fixed on a 2D substrate. The research team found that this catalyst can efficiently accelerate the removal of hydrogen atoms from liquid chemical carriers, and the material is very sturdy, made from abundant metals rather than existing precious metals, which will help make hydrogen a source of energy for various applications.

These types of catalysts are commonly used to accelerate the rate of chemical reactions, while the compound itself is not consumed, but can maintain a specific molecule in a stable position or act as an intermediary, allowing an important chemical step to be completed smoothly. As for chemical reactions that can generate hydrogen gas from liquid carriers, efficient catalysts are generally made of expensive metals. However, such catalysts are usually expensive, have limited reserves, and are prone to contamination. However, cheaper catalysts made from ordinary metals often have lower efficiency and poorer stability, limiting their activity and practical application in the hydrogen production industry.

In order to improve catalysts made from abundant metals, researchers have changed their strategy and focused on small, uniform nickel metal clusters. This type of metal cluster is very important as it allows a certain amount of material to be exposed to the active surface to a maximum extent. However, metal clusters are also prone to clustering together, leading to limited reaction capacity.

Researchers designed and conducted an experiment to prevent metal clusters from clustering together by depositing 1.5 nanometer sized nickel clusters on a 2D substrate. The 2D substrate is made of boron and nitrogen and is designed as an atomic sized grid with grooves. The nickel cluster will be uniformly and firmly fixed in the groove. This design not only prevents the aggregation of metal clusters, but also greatly improves the thermochemical performance of the catalyst by directly interacting with nickel metal clusters, thereby enhancing its overall performance.

Researchers have utilized detailed X-ray and spectroscopic measurements, combined with theoretical calculations, to reveal many subsurface conditions and their roles in catalytic reactions. The Berkeley Laboratory uses advanced photon source tools and computational modeling methods to identify changes in the physical and chemical properties of the 2D substrate when small nickel metal clusters form and deposit on it. The research team proposed that when metal clusters occupy the original area of the substrate and interact with nearby edges, the material forms, allowing for the preservation of the tiny size of the metal clusters. This small and stable metal cluster promotes the separation of hydrogen from the liquid carrier, giving the catalyst excellent separation, productivity, and stability.

Calculations show that the size of the catalyst enables it to be more active than other catalysts with better performance. Researchers have used models and computational methods to reveal the unique geometric and electronic structure of this tiny metal cluster. A large number of exposed metal atoms gather on such small clusters, and larger metal particles are more attractive to hydrogen carriers. Such exposed atoms can also slow down the step of hydrogen detachment from the carrier, while preventing the formation of pollutants that may clog the surface of the cluster. Therefore, this material can remain uncontaminated during the critical steps of hydrogen production reactions. This type of catalytic and anti pollution performance was intentionally introduced into the 2D substrate, ultimately resulting in the cluster being able to maintain a smaller size.

In this study, researchers successfully developed cheaper, easier to obtain, and more stable materials that can help remove hydrogen from liquid carriers, enabling hydrogen to be used as a fuel. This study is based on a plan by the US Department of Energy aimed at studying hydrogen storage materials that can meet the requirements of the Energy Efficiency and Renewable Energy (EERE) Hydrogen and Fuel Cell Office, and optimizing materials for future use in vehicles.

In the future, the Berkeley laboratory team will further refine their strategy to modify the 2D substrate to provide support for small metal clusters, thereby developing more efficient catalysts. This technology helps optimize the process of extracting hydrogen from liquid chemical carriers.

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