I was chatting recently with an academic friend about the merits of homogeneous gold catalysis in organic chemistry (inspired by our recent review on the subject), and he expressed the opinion that it was just platinum chemistry in disguise. Then he surprised me by saying “But we need gold chemistry, because we’re going to run out of platinum in a few years time.” On further questioning, he said that the demand for platinum has increased enormously (not least because it is used in catalytic converters in cars), so that Earth’s limited supplies are running out. He believes that the same applies to rhodium, for much the same reasons.

This reminded me of various random snippets that I’ve heard about other ‘endangered’ elements. For example, the US stockpiles helium and the Netherlands has been recycling it for years. Indium is incredibly useful as a component of indium tin oxide — an optically transparent electrical conductor — but supplies are low and alternatives are needed.

Even the price of copper has shot up recently, because of the increased demand in rapidly developing economies such as China and India. There have been reports in the UK of copper wiring and pipes being stolen from building sites, and even from train tracks and people’s homes. I don’t think there’s any danger of Earth’s copper supplies running out — it’s far more abundant than the other elements mentioned — but it’s interesting to see that previously uneconomical sources are now being seriously considered for exploitation (for example, see the recent article on deep sea mining in Chemistry World).

Intriguing stuff, and maybe something that we should be seriously thinking about. Does anyone know of other useful elements that might be running out?

Andy

Andrew Mitchinson (Associate Editor, Nature)