A new catalyst arrangement has accelerated the process of water electrolysis.

Hydrogen is crucial for science and industry due to its properties: it is the lightest chemical element, possesses a high energy density, making it a fuel that does not produce hazardous emissions. The only combustion product of hydrogen is water. When oxidized, hydrogen combines with two oxygen atoms to form water, H₂O.

These characteristics render hydrogen an attractive source of “clean energy.” However, its production still consumes a significant amount of energy. Researchers are striving to enhance the efficiency of water electrolysis so that renewable energy sources can facilitate the process of hydrogen production.

Water electrolysis is the process by which water is decomposed into its constituent elements under the influence of an electric current. Water is brought into contact with electrodes, the cathode and the anode, through various methods. A current source is connected to the electrodes. When the current flows, hydrogen is produced at the cathode, and oxygen is generated at the anode. These gases quickly accumulate from free atoms into molecular hydrogen (H₂) and oxygen (O₂).

The relatively slow physicochemical process of breaking down water into oxygen and hydrogen is referred to as the oxygen evolution reaction (oxygen evolution reaction, OER). Accelerating OER can be achieved using catalysts made from noble metals. Gold, silver, platinum, and iridium are rare and expensive metals, and additional energy is required to enhance the reaction involving them.

An international research group has developed a new method for the electrochemical splitting of water. The results of the study have been published in the journal Nature Nanotechnology.

The new approach utilizes atomically dispersed iridium as a catalyst. The metal is embedded within a structure composed of dimethylimidazole and cobalt and iron hydroxides. An important innovation from the research group lies in the arrangement of these components: they are assembled into a three-dimensional structure, which has improved the efficiency and productivity of water decomposition.

The method proposed by the scientists significantly enhances the activity of OER and requires minimal additional energy. The three-dimensional structure utilizes only individual iridium atoms, which reduces the cost of using the catalyst and stabilizes the accelerated reaction.