In the quest for sustainable energy solutions, hydrogen has emerged as a promising contender due to its versatility and zero-emission potential. One of the key methods for producing hydrogen is through water electrolysis, a process that separates water into hydrogen and oxygen using electricity. The need for considerable amounts of freshwater, however, presents challenges to areas where plentiful water supplies are limited.

Consequently, it is essential to create a new water electrolysis method that can directly utilize earth’s plentiful seawater supply. Putting the impurities of seawater aside, saltwater electrolysis is a potential solution for electrolysis where freshwater supply is restricted. Similar to freshwater electrolysis, saltwater electrolysis involves passing an electric current through the solution, causing water molecules to dissociate, with hydrogen gas evolving at the cathode and oxygen gas evolving at the anode. The sodium ions from the salt remain in the solution, while chloride ions combine with the oxygen ions to form hypochlorite ions.

One issue with the use of saltwater is decreased durability of the electrodes and catalysts due to excessive corrosion. However, ongoing research and development efforts, coupled with growing public and private sector investments, are driving progress towards overcoming these challenges.
At the University of Tsukuba of Japan, a research group has developed a multi-elemental alloy electrode composed of nine non-metal elements with results suggesting improved anode performance.

At the University of Adelaide of Australia, a setup is being tested with an “electrolyzer that uses a membrane permeable only to H+ ions. This setup split water molecules at the anode instead of the cathode, snatching away electrons to free H+ ions. The ions migrate through the membrane to the cathode where they combine with electrons to make H2.”

At the Royal Melbourne Institute of Technology, Australia, Dr. Nasir Mahmood and researchers are testing a unique catalyst composed of porous sheets of nitrogen-doped NiMo3P (N-NiMo3P) which increases electrical conductivity and improves anti-corrosive properties.

Saltwater electrolysis represents a promising avenue for sustainable hydrogen production, leveraging the abundant resource of seawater to generate clean energy. As research and development efforts continue to advance, saltwater electrolysis holds the potential to play a pivotal role in the global transition towards a hydrogen-based economy.