New Catalyst to Extract Hydrogen from Hydrogen Storage Materials

The U.S. Department of Energy’s Ames Laboratory and collaborators have developed a new catalyst to extract hydrogen from hydrogen storage materials easily.

Scientists Long Qi and Wenyu Huang, who led the research, developed a new catalyst composed of nitrogen and carbon that does not require metal or additives. The catalyst’s efficiency relies on the structure of nitrogen. The hydrogen extracted was from a class of materials called liquid organic hydrogen carriers (LOHCs).

Hydrogen can be stored chemically, and it relies on materials that react with hydrogen molecules and store them as hydrogen atoms like in LOHCs. These carriers can store large amounts of hydrogen in small volumes at ambient temperature. To utilize hydrogen, catalysts are needed to activate LOHCs and release the hydrogen.

Long Qi said, “Basically, just add the new metal-free catalyst into the LOHC, and then the hydrogen gas is just popping out, even at room temperature.”

The catalytic activity could occur at room temperature because of the unique closely spaced graphitic nitrogen as nitrogen assembly was formed during the carbonization process. The nitrogen assembly catalyzes the splitting of carbon-hydrogen bonds in LOHCs and facilitates the desorption of hydrogen molecules.

The researchers said the process occurs at mild temperatures and under normal atmospheric conditions without using metals or additives. The new catalyst offers a promising new solution that addresses long-standing challenges in adopting hydrogen fuel for transportation and other applications.

The researchers explained that there are other dehydrogenation methods. However, some methods rely on metal-based catalysts involving critical platinum group metals. The metals are expensive, and their supply is limited. Other methods require additives to release the hydrogen that is not reusable, resulting in a higher overall cost as they need to be added in each cycle.

The hydrogen storage capacity should be close to 6.5% by weight as per the Department of Energy’s goals for vehicle technology. The researchers are optimistic about meeting the goal with molecules that have a larger capacity.

The researchers said the ease and efficiency of this process could benefit the industry in the future, which comes from using a combination of LOHCs and the new catalyst. The combination would extract usable hydrogen from storage at a lower cost and under milder conditions than existing technologies. A greater hydrogen density can provide a greater charge for hydrogen fuel cells, providing power to vehicles over greater distances.

In October 2021, a team of scientists from the Institute of Nano Science and Technology claimed to have developed a prototype reactor that operates under natural sunlight to produce around 6.1 liters of hydrogen in eight hours. The team used carbon nitrides as a catalyst.

Mercom had earlier reported that a research team from Newcastle University, Australia, devised a system that uses solar power to conduct electrolysis on water harvested from air to create hydrogen, a low-cost zero-emission fuel.