PROVIDENCE – Two Brown University chemists appear to have overcome a key challenge to the use of palladium as a less-expensive catalyst in fuel cells, according to research published in the online edition of the Journal of the American Chemical Society.

Palladium (Pd) is far cheaper than platinum (Pt) – another metal used to catalize, or jump start, the chemical reaction that converts fuel to electricity within a fuel cell – and it also is far more abundant. But until now, researchers have struggled find a way to create palladium particles with enough surface area to make catalysis efficient, yet keep those particles from clumping together during the chemical reaction they are there to speed up.

Now, the Brown researchers have succeeded in producing palladium nanoparticles with a surface area about 40 percent greater than previously achieved. Their particles also stay intact about four times longer than those currently available, they wrote in an article entitled “Oleylamine-Mediated Synthesis of Pd Nanoparticles for Catalytic Formic Acid Oxidation.”

“This approach is very novel. It works,” said Vismadeb Mazumder, a graduate student who co-authored the paper with chemistry Prof. Shouheng Sun. “It’s two times as active, meaning you need half the energy to catalyze. And it’s four times as stable.”

Mazumder and Sun created palladium nanoparticles 4.5 nanometers (nm) in size. They attached the nanoparticles to a carbon platform at the anode end of a direct formic-acid fuel cell. Then they did something new: They used weak-binding amino ligands to help keep the nanoparticles separate and uniform in size as they are attached to the carbon platform. That, they say, increased the available surface area on the platform and raised the efficiency of the fuel cell reaction.

“These Pd particles hold promise as a highly active non-Pt catalyst for fuel cell applications,” Mazumder and Sun wrote in the abstract for their American Chemical Society posting. But in a university news release, Sun put it more simply: “It just works better,” he said.

Their work may “virtually double” the efficiency of the metal as a catalyst, Jon Nadler, a senior analyst at Kitco Inc. in Montreal, wrote in a research note yesterday, according to Bloomberg News.

The research was financed by the National Science Foundation’s Division of Materials Research and the Research Seed Fund of Brown University’s Office of the Vice President for Research. Now, the duo are continuing their work, seeking palladium-based catalysts with enhanced activity and stability for future fuel-cell applications.

Brown University is an Ivy League institution offering nearly 100 programs of study to its nearly 7,200 undergraduate, graduate and medical students. For more information, visit www.brown.edu.