Electrolysis: producing hydrogen from water

The electrolysis of water is a promising method for obtaining hydrogen. Water (H₂O) is broken down into its components, hydrogen (H₂) and oxygen (O₂), using electrical energy. This process offers an environmentally friendly alternative to fossil fuels and plays a key role in sustainable energy supply.

How electrolysis works

At the heart of electrolysis are two electrodes, an anode and a cathode, which are immersed in an aqueous solution. When an electrical voltage is applied, the oxidation of water to oxygen takes place at the anode, while the reduction of water to hydrogen takes place at the cathode. The reaction equations are as follows: Anode (oxidation): 2H₂O → O₂ + 4H⁺ + 4e- Cathode (reduction): 4H₂O + 4e- → 2H₂ + 4OH- The hydrogen produced is collected as a gas at the cathode. The main advantages of electrolysis are the high purity of the hydrogen produced and the possibility of using surplus renewable energy. Especially when combined with solar or wind power, electrolysis can be operated almost emission-free.

The challenges of electrolysis

There are a number of challenges to overcome: The energy efficiency of electrolysis is around 60-80%, which means that a considerable amount of the electrical energy used is lost in the form of heat. In addition, the costs of electrolysers and the electrical energy required are currently still relatively high, which impairs the competitiveness of green hydrogen.

Future prospects

However, advances in materials science and economies of scale could improve economic efficiency in the near future. Research is focusing in particular on the development of new electrode materials and electrolyte systems to increase efficiency and reduce operating costs. In summary, electrolysis is a promising technology for environmentally friendly hydrogen production. It plays a crucial role in sustainable energy supply and could be a central pillar of the global energy transition in the future.