Blatant Reality

A new catalyst has been developed that separates the Oxygen from a water molecule. The hope is that with this cheap catalysts, researchers will be able to develop a way for the sun to power the necessary reaction, thus creating a new, sustainable source of energy.

Daniel Nocera, a professor of chemistry at MIT, has developed a catalyst that can generate oxygen from a glass of water by splitting water molecules. The reaction frees hydrogen ions to make hydrogen gas. The catalyst, which is easy and cheap to make, could be used to generate vast amounts of hydrogen using sunlight to power the reactions. The hydrogen can then be burned or run through a fuel cell to generate electricity whenever it’s needed, including when the sun isn’t shining.

 

Solar power is ultimately limited by the fact that the solar cells only produce their peak output for a few hours each day. The proposed solution of using sunlight to split water, storing solar energy in the form of hydrogen, hasn’t been practical because the reaction required too much energy, and suitable catalysts were too expensive or used extremely rare materials. Nocera’s catalyst clears the way for cheap and abundant water-splitting technologies.

 

Nocera’s advance represents a key discovery in an effort by many chemical research groups to create artificial photosynthesis–mimicking how plants use sunlight to split water to make usable energy. “This discovery is simply groundbreaking,” says Karsten Meyer, a professor of chemistry at Friedrich Alexander University, in Germany. “Nocera has probably put a lot of researchers out of business.” For solar power, Meyer says, “this is probably the most important single discovery of the century.”

However, this still doesn’t solve all the problems with using hydrogen as a fuel. Another catalyst needs to be developed to create hydrogen ions that is cheaper than the current platinum ones used.

Nocera created the catalyst as part of a research program whose goal was to develop artificial photosynthesis that works more efficiently than photosynthesis and produces useful fuels, such as hydrogen. Nocera has solved one of the most challenging parts of artificial photosynthesis: generating oxygen from water. Two more steps remain. One is replacing the expensive platinum catalyst for making hydrogen from hydrogen ions with a catalyst based on a cheap and abundant metal, as Nocera has done with the oxygen catalyst.

 

Finding a cheaper catalyst for making hydrogen shouldn’t be too difficult, says John Turner, a principal investigator at the National Renewable Energy Laboratory, in Golden, CO. Indeed, Nocera says that he has promising new materials that might work, and other researchers also have likely candidates. The second remaining step in artificial photosynthesis is developing a material that absorbs sunlight, generating the electrons needed to power the water-splitting catalysts. That will allow Nocera’s catalyst to run directly on sunlight; right now, it runs on electricity taken from an outlet.

While this is definitely a promising step in the right direction, I wouldn’t hold my breath until they will discover the necessary catalyst.