Answering a Few Questions About Alkaline Electrolysis

Electrolysis is a process that uses direct electric current to drive chemical reactions that don’t occur spontaneously.
Water electrolysis to produce green hydrogen is an electrolysis application that breaks water molecules into their constituents – hydrogen and oxygen – using renewable energy. 

To know more about this centenarian technology and how it has been evolving since, we interviewed our expert, Michele Perego, Product Manager for the Energy Transition and Hydrogen Business Unit at De Nora. 

Primarily, Alkaline water electrolysis (AWE) was developed over a century ago and is the most mature water electrolysis technique for large-scale production of green hydrogen to date. Over the decades, it has undergone substantial technological progress, moving from traditional AWE to more advanced setups, as traditional water electrolysis methods can be energy-intensive, inefficient, and counterproductive for industrial applications. 

Advanced water electrolysis was born as a consequence of these major developments in the field: 

• The use of advanced materials such as electrocatalytic coatings in place of bare nickel, 
  
  

• The adoption of the zero-gap configuration, 
  
  

• The utilization of thinner diaphragms. 

These improvements significantly enhanced the cell’s efficiency by reducing electrical resistance, thereby minimizing energy losses. 

Electrocatalytic coatings are a mixture of platinum-group and rare-earth metals, appropriately formulated, which are applied to a metal support, generally bare nickel, and have the critical function to speed up the electrochemical reaction of water splitting. Using these advanced catalytic materials primarily reduces the additional cell voltage required to initiate electrolysis beyond the thermodynamic potential. 

Progress in materials science was followed by significant improvements in cell design. In this sense, a pivotal innovation was the adoption of a zero-gap electrode configuration, an alternative to the finite-gap configuration. This novel design means that the anode and cathode are in direct contact with the diaphragm, thereby reducing ohmic drops.

De Nora’s pioneering spirit has been instrumental in translating electrochemical science into robust industrial technologies. The discovery of the mixed-metal oxide electrodes, later commercialized under the DSA® brand, laid the foundation for the development of activated electrodes for advanced water electrolysis.  

As outlined by our contributions to the most visionary green hydrogen projects worldwide, De Nora is a reliable, trusted, and credible partner to enable and scale up capacity at an unprecedented scale. Notably, we delivered more than 3.1 GW of electrolysis capacity by the end of 2025, laying the foundation for this sector from the very beginning. 

We would like to thank Michele for sharing is insight and teaching us more about advanced electrolysis solutions and how De Nora’s contribution is pivotal to enable the green hydrogen market.