reportedly discovered a compound , ethylammonium lead iodide , that can safely and efficiently store and release ammonia . This discovery has the potential to serve as a hydrocarbon-free carrier, contributing to the transition to a decarbonized society.
The findings were recently published in the Journal of the American Chemical Society. It is claimed that it can not only store ammonia safely and conveniently, but also store the important hydrogen it carries.
In order for society to move from carbon-based energy to hydrogen-based energy, we need a safe way to store and transport hydrogen, which is itself highly combustible. One way is to store it as part of another molecule and extract it when needed. Ammonia, with the chemical formula NH3, is a good hydrogen carrier because there are three hydrogen atoms in each molecule, and ammonia is almost 20% hydrogen by weight. The problem,
however, is that ammonia is a very corrosive gas that is difficult to store and use. Currently, ammonia is typically stored in pressure-resistant containers by liquefying at temperatures well below freezing. The porous compound can also store ammonia at normal temperature and pressure, but the storage capacity is low, and the ammonia is not easy to recover.
The latest study reports the discovery of a perovskite, a material with a unique repeating crystal structure, which can easily store ammonia and can also be recovered intact (restored to a usable state) at relatively low temperatures.
Specifically, the research group focused on the perovskite ethyllead ammonium iodide (EAPbI3), which has the chemical formula CH3CH2NH3PbI3. They found that its one-dimensional columnar structure would chemically react with ammonia at room temperature and pressure and dynamically transform into a two-dimensional layered structure called lead hydroxide or Pb (OH) I. As a result of
this process, ammonia is stored in the layered structure by chemical conversion. For this reason, EAPbI3 can safely store corrosive ammonia as a nitrogen compound in a much cheaper process than liquefaction in a pressure vessel at -33 ° C. What's more, the process of recovering the stored ammonia is just as simple. "To our surprise, ammonia stored in ethylammonium lead iodide can be easily extracted with only a little heat," the
researchers said.
They further explained that the stored nitrogen compounds would undergo a reverse reaction at 50 ° C under vacuum conditions and convert back to ammonia. This temperature is well below the 150 ° C or higher required to extract ammonia from porous compounds. As such, EAPbI3 is a simple, cost-effective and excellent medium for handling corrosive gases.
In addition, the perovskite can be reused after recovering the one-dimensional columnar structure, so that ammonia can be stored and extracted repeatedly. An added benefit is that the normally yellow compound turns white after the reaction. Kawamoto said, "The compound can change color when storing ammonia, which means that color-based ammonia sensors can be developed to determine the amount of ammonia stored." The new storage method is
said to have multiple uses. In the short term, researchers have developed a safe way to store ammonia that already has multiple uses in society, from fertilizers to pharmaceuticals to textiles.
"In the long run, we hope that this simple and effective method can be a part of the solution to decarbonization by using ammonia as a carbon-free hydrogen." They added.
浙公网安备33010802003254号