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An environmentally friendly future must not only encompass a universe where recycled materials are continuously repurposed, but must also involve the complete elimination of pollution from all its causes. One of the largest attributes of air pollution today is a result of the combustion of fuels powering factories and automobiles that produce carbon dioxide (CO2) as a byproduct.
In an effort to move towards this healthier vision of a universe, the “hydrogen economy” has provided a glimpse into what a sustainable and environmentally friendly future could look like.
The hydrogen economy describes a system that utilizes hydrogen, an attractive chemical for its ability to be stored for later use, as a major carrier for energy supply purposes1. As a result of hydrogen’s combustibility, it has successfully been used as a fuel, both by itself and in combination with traditional gasoline.
Hydrogen is typically stored in a unit known as a fuel cell, which is a term used to describe a battery capable of storing energy in a highly efficient manner, as compared to conventional combustion engines.
With an estimated 60% efficiency attributed to the use of fuel cells, which is comparable to that of a gasoline internal combustion engine, whose efficiency typically only ranges from 20-35%, these energy storage devices also exhibit a decreased rate of pollution production as compared to these typical fuel methods. In fact, a hydrogen-powered fuel cell will only produce water, heat and electricity following its use in any type of vehicle or device1.
As a result of the remarkably eco-friendly effects associated with hydrogen-powered vehicles, an increased interest in developing enhanced methods of storing hydrogen for these energy purposes is captivating the attention of many researchers around the world.
A recent collaboration between scientists from Lawrence Livermore and Sandia National Laboratories has successfully developed an efficient hydrogen storage system placed under nanoconfinement. The method of nanoconfinement describes the infiltration of a metal hydride with the matrix of another material, typically carbon2.
By placing a high-capacity lithium nitride (Li3N) hydrogen storage system under this process of nanoconfinement, these researchers have shown that both the uptake and release of hydrogen within its given pathways were changed dramatically2. These changes occurred as a direct result of the presence of nanointerfaces present on the lithium nitride nanoparticles, which measured at a width of only 3 nanometers, allowing for a unique control of the hydrogen storage reaction chemistry to take place2.
By undergoing a series of hydrogenation reactions, the application of lithium nitride nanoparticles to this system completely avoids the production of unfavorable intermediates, therefore increasing the efficiency of the hydrogen fuels3. Typical hydrogen fuel used in combination with air can cause a subsequent production of harmful nitrogen oxides (NOx) intermediates, which can be damaging to the vehicle or device, as it can slow down the ability of the material to perform adequately1. By enhancing the storage capacity of this system through the utilization of these confined nanoparticles, a completely new paradigm for hydrogen storage methods has been established.
While the use of solid-solid nanointerfaces is not new to the world of battery applications, this is the first time that the role of these interfaces has shown to be successful for hydrogen storage purposes3.
As a result of changing the chemical reactions occurring at the internal microstructures within the hydrogen storage systems, researchers in this study have been able to further understand the importance of considering not only this internal microstructure, but also the certain morphological properties that can greatly affect the performance of a given material.
By understanding the function of hydrogen-induced phase transitions in the presence of complex metal hydrides, future engineering materials are now able to take this work further in future energy storage endeavors.
- Bennaceaur, Kamel, Brian Clarke, Franklin M. Orr, Jr., T. S. Ramakrishnan, Claude Roulet, and Ellen Stout. "Hydrogen as a Future Energy Carrier." ECLIPSE 300 (2005): 30-41. Web.
- "Nano-sized Hydrogen Storage System Increases Efficiency." ScienceDaily. ScienceDaily, 24 Feb. 2017. Web. https://www.sciencedaily.com/releases/2017/02/170224133918.htm.
- "Researchers Use Confined Nanoparticles to Improve Hydrogen Storage Materials Performance." Phys.org. 24 Feb. 2017. Web. https://phys.org/news/2017-02-confined-nanoparticles-hydrogen-storage-materials.html.