Stanford University scientists have invented a low-cost water splitter that uses a single catalyst to produce both hydrogen and oxygen gas 24 hours a day, seven days a week. The mysterious workings of a new catalyst could help produce fuels from water and improve fuel cells.

Splitting water into its constituent hydrogen and oxygen elements is an important starting point for the development of clean renewable fuels. Producing hydrogen from water could also become a method to store excess renewable energy. The device, described in a study published June 23 in Nature Communications, could provide a renewable source of clean-burning hydrogen fuel for transportation and industry.

Hydrogen has long been promoted as an emissions-free alternative to gasoline. Despite its sustainable reputation, most commercial-grade hydrogen is made from natural gas, a fossil fuel that contributes to global warming. As an alternative, scientists have been trying to develop a cheap and efficient way to extract pure hydrogen from water.

A conventional water-splitting device consists of two electrodes submerged in a water-based electrolyte. A low-voltage current applied to the electrodes drives a catalytic reaction that separates molecules of H2O, releasing bubbles of hydrogen on one electrode and oxygen on the other.

Jaramillo and his collaborators sought to develop a catalyst for the oxygen evolution reaction, the notoriously slow half of the water-splitting process. A catalyst is a substance that speeds up a chemical reaction or lowers the energy required to get it started without getting used up itself. Making these materials last longer, work faster and use less energy would cut prices and improve efficiency in producing renewable hydrogen.

They are still looking forward to develop a better catalyst which is a million times better than what they have developed. But this finding could change the way we use fuels currently.