Nickel and phosphorus nanoparticles may provide a simple, inexpensive solution to catalyze hydrogen-producing reactions, feeding the growth of fuel cell technology.
A chemistry professor at Penn State University, Raymond Schaak, has determined that phosphorus and nickel, two inexpensive, plentiful materials, can lower the energy needed to turn water into hydrogen and oxygen, an essential step to creating fuel cells. Inexpensive effective fuel cells could one day power everything from small electronic devices to cars. Used in solar or wind farms, fuel cells can help smooth the output from the facilities when sunlight or wind are lacking.
Hydrogen is a perfect fuel for such devices, and the element is present in large quantities in water. It normally requires a great deal of energy to split the water into its component gases, however. To lower the energy required for the reaction to take place, a catalyst is introduced to the reaction. One of the best materials currently used is platinum, but that metal is costly. This cost keeps water-produced hydrogen from being economically feasible for commercial production.
"There were some predictions that nickel phosphide might be a good candidate. It turns out that nanoparticles of nickel phosphide are indeed active for producing hydrogen and are comparable to the best known alternatives to platinum," Schaak said.
Nanoparticles for this experiment were created from metal salts dissolved in a solvent, along with different chemicals. This mixture was then heated. The particles produced were quasi-spherical. Not quite ball-shaped, the tiny particles have ridges around them, which increases the surface area where reactions can take place.
Tests were performed on the catalyst by spreading the nanoparticles on a sheet of titanium foil which was then immersed in sulfuric acid. When electricity was run through the system, the catalyst performed as hoped.
"The goal now is to further improve the performance of these nanoparticles and to understand what makes them function the way they do. Also, our team members believe that our success with nickel phosphide can pave the way toward the discovery of other new catalysts that also are comprised of Earth-abundant materials," Schaak said.
The project was funded by the National Science Foundation and the Department of Energy. Research into the new catalyst was presented in the Journal of the American Chemical Society.
