Because fuel cells are reliant on platinum as a catalyst, they and the devices they power have remained too expensive for widespread adoption, says the team.
Nanowires with jagged, rather than smooth, surfaces create new types of highly active sites that can reduce the reaction barrier and speed the oxygen reduction reaction. The team notes the thin body of the nanowire ensures more platinum atoms are exposed on the surface and participate in the reaction. According to the findings, jagged nanowires are so active that the amount of platinum needed to make one fuel cell today could be used to make 50 jagged nanowire fuel cells.
“This work is a perfect example of what one can achieve by the atomic scale control of nanoscale materials and how structural modifications at such small dimension can lead to big gain in functions for real applications,” said Professor Yu Huang from UCLA’s Henry Samueli School of Engineering and Applied Science. “This is fascinating world to explore for a material scientist.”
The researchers created the wires in a two-step process. First, they used made nanowires from a platinum-nickel alloy. Then an electrochemical process remove nickel atoms from the alloy, leaving what looks like fuzzy wires composed of only platinum.
Also involved in the work were the National Research Council of Italy, Tsinghua University, the Chinese Academy of Sciences, California State University, Long Beach, Northeastern University and Lawrence Berkeley National Laboratory.
