Thursday, December 25, 2008

Low-cost fuel cells a step closer

Low-cost fuel cells a step closer Chinese researchers develop a nickel catalyst
by Helen Tunnicliffe

A GROUP OF scientists from Wuhan University in China have developed a hydrogen fuel cell using a nickel-based catalyst and an alkaline electrolyte, which they believe is a viable alternative to expensive platinum catalysts and acidic electrolytes currently in use.

Shanfu Lu, Jing Pan, Aibin Huang, Lin Zhuang and Juntao Lu developed an alkaline electrolyte - the polymer quaternary ammonium polysulphone – which can conduct hydrogen ions. They used silver for the positive electrode and chromium-decorated nickel for the negative electrode.

“The surface electronic structure of nickel has been tuned to suppress selectively the surface oxidative passivation with retained activity toward hydrogen oxidation,” states the abstract.

In other words, the chromium has changed the surface electronic structure of the nickel to prevent it from being oxidised (which would otherwise reduce its effectiveness) while still allowing the catalysis of the reaction of hydrogen ions which produces the electrical current.

Most hydrogen fuel cells in use today are acidic and corrode metals. Most research has, therefore, concentrated on catalysts made from precious metals, usually platinum, which are stable in acidic conditions. However, their high cost has prevented a greater uptake of the technology. The scientists believe their discovery to be an important advance in fuel cell technology.

The paper was published in the journal Proceedings of the National Academy of Sciences (PNAS).
Source: tcetoday, Friday 26 December 2008

No comments: