Storing Hydrogen

Researchers at the RIKEN Center for Emergent Matter Science (CEMS) in Japan have found a simple and affordable way to store ammonia, an important chemical in a range of industries. The discovery could also help in establishing a hydrogen-based economy.

Ammonia, chemically written as NH3, is widely used across industries ranging from textiles to pharmaceuticals and is an important component in the manufacture of fertilizers. For its current use, ammonia is stored in pressure-resistant containers after liquefying it at temperatures of -27 Fahrenheit (-33 degrees Celsius).

Alternate methods of storing ammonia in porous compounds have been explored. The storage and retrieval process can be achieved at room temperature, but the storage capacity of these compounds is limited.

A research team led by Masuki Kawamoto at RIKEN CEMS has now found that perovskites, crystalline structures associated with improving energy conversion efficiencies of solar panels, can also serve as an excellent medium for the storage and retrieval of ammonia.

Perovskite as an ammonia carrier
Kawamoto's team found that the perovskite ethyl ammonium lead iodide (EAPbI3) reacts with ammonia at room temperature and pressure to make lead iodide hydroxide, or Pb(OH)I. Ethyl ammonium lead iodide has a one-dimensional columnar structure but, after reacting with ammonia, forms a two-dimensional layered structure.

Ammonia is a highly corrosive gas, but the chemical reaction with the perovskite allows for its safe storage that does not need any special equipment to store it either. The retrieval process is also very straightforward. Under vacuum, ethyl ammonium lead iodide can be heated to 122 Fahrenheit (50 degrees Celsius) to release ammonia gas.  READ MORE...