A novel catalyst developed by the US Department of Energy’s Ames Laboratory and partners efficiently recovers hydrogen from hydrogen storage materials.
The procedure is carried out at low temperatures and under normal atmospheric conditions, with no metals or additives used. The breakthrough promises a potentially game-changing new answer to a long-standing issue in the use of hydrogen as a transportation and other fuel source.
Hydrogen as a fuel could be a part of a national strategy to minimize reliance on fossil fuels. According to the DOE, increasing hydrogen storage capacity is critical for the advancement of hydrogen fuel cell technology. Long Qi and Wenyu Huang of Ames Laboratory are investigating the extraction of hydrogen from a class of compounds termed liquid organic hydrogen carriers (LOHCs).
Chemical storage is one method of storing hydrogen. Chemical storage is based on materials that react with hydrogen molecules and store them as hydrogen atoms, such as in low-temperature hydrogen storage (LOHCs). At ambient temperatures, this sort of storage allows for the storage of huge amounts of hydrogen in small volumes. However, catalysts are required to activate LOHCs and release the hydrogen. This is referred to as dehydrogenation.
Qi said that while there are various dehydrogenation methods available at the moment, they do have certain drawbacks. Certain techniques make use of metal-based catalysts containing essential platinum group metals. These metals are scarce and expensive. Other procedures necessitate the addition of chemicals to release the hydrogen. These additives are not recyclable and result in increased total expenses due to the fact that they must be added on a per-cycle basis.
Qi and Huang discovered a catalyst that does not require metals or chemicals. “It’s quite straightforward,” Qi stated. “Essentially, all that is required is to insert the metal-free catalyst into the LOHC, and the hydrogen gas will flow out at normal temperature.”
Catalysts are composed of nitrogen and carbon. The structure of the nitrogen is critical to its efficiency. At room temperature, catalytic activity is possible due to the peculiar, tightly spaced graphitic nitrogen molecules generated during the carbonization process. The nitrogen arrangement in LOHCs catalyzes the breaking of carbon-hydrogen (C-H) bonds and enables hydrogen molecule desorption. This technique increases the efficiency of the catalyst relative to other catalysts employed.
According to Qi and Huang, a hydrogen storage capacity of almost 6.5 percent by weight is required to meet DOE’s vehicle technology targets. They are enthusiastic about the future of their study, which will focus on developing molecules with increased capacity.
“This research will contribute to the goal of carbon dioxide emission reduction,” Huang explained, “and we will need to build more effective catalytic systems.”
Transportation accounted for 29% of all carbon dioxide emissions in the United States in 2019. Qi stated that the process’s simplicity and efficiency could assist the transportation industry in the future. The advantages stem from the combination of LOHCs and a catalyst of this type. This combination enables the extraction of usable hydrogen from storage at a lower cost and under more benign conditions than current approaches. Increased hydrogen density can give a more powerful charge for hydrogen fuel cells, allowing vehicles to travel longer distances.
Both Qi and Huang stressed the importance of this discovery in advancing the country’s goal of being carbon neutral by 2050 by developing a simple and effective method for dehydrogenating LOHCs.
