Wednesday, 7 October 2009

Highlights: Nanotube electrocatalysts, pentagonal prisms and corroding platinum

Carbon nanotubes can do anything, it seems. And now vertical arrays of nitrogen-doped CNTs have been found to be effective oxygen reduction electrodes, for use in fuel cells. Another cheaper alternative to platinum, which is the usual material used.

According to valence shell electron pair repulsion rules (VSEPR - remember learning those in long-ago undergrad days?), what structure would you expect a compound with 10 Ge atoms around 1 Co? Distribute all those bonds equally and you'd get a bicapped square antiprism. But instead you get a nearly geometrically perfect pentagonal prism — even the Ge–Ge distances BETWEEN the pentagonal faces are nearly the same as those WITHIN the faces.

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