Gold Innovations Blog

Alkaline fuel cells have been around for years. The Space Shuttle fuel cells (and fuel cells used on the Apollo missions before them) have all used alkaline fuel cells. This is interesting for us working in precious metals because the commonly used Nafion fuel cell membrane operates under acid conditions and requires the use of platinum electrocatalysts. However, under alkaline conditions the chemistry of the fuel cell is obviously very different and it means that the platinum group metals are not necessarily the best electrocatalysts in the fuel cell. For example, World Gold Council sponsored work a couple of years ago that showed gold electrocatalysts were very promising alternatives for oxygen reduction in fuel cells operating under alkaline conditions. However, in order to exploit this what is needed is a reliable alkaline alternative to nafion i.e. an anion exchange membrane.

In a recent development Yushan Yan, chemical and environmental engineering professor at the University of California, Riverside, and his team have developed an alkaline membrane, which contains the polymeric ionomer TPQPOH with a tris(2,4,6-trimethoxyphenyl)phosphonium unit. TPQPOH is very soluble in low-temperature water-soluble solvents, and has high ionic conductivity and alkaline stability. The membrane works on the basis of hydroxide ion exchange rather than hydrogen ion exchange. We’ll be keeping an eye on this development and what it may mean for gold in fuel cells…..