Platinum’s Precious Problem

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Platinum Crystals. Via Wikimedia Commons

 

It’s heavy, it’s shiny and for the low price of around $50,000 a kilo it can be yours.

Platinum is best known as for being the one up from gold when it comes to bling, credit cards and record sales. Like gold, it’s an expensive soft metal with a beautiful pale luster,  and astonishingly rare.  Rappers cant seem to stop talking about it, but neither can engineers.

WHAT IS PLATINUM USEFUL FOR

While platinum itself doesn’t react with much, it does an excellent job of making other things react. This means it’s found many uses to enable or significantly speed up reactions. It’s the catalyst in catalytic converters, stopping polluting carbon monoxide and nitrogen oxide coming out of cars any more. This use is so widespread, 44% of the platinum mined every year is used on this, even though only a few grams are required for each converter. In industry, it also has many uses as a catalyst for an enormous variety of reactions, like naptha cracking, oil hydrogenation and nitrate production.

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Platinum also cures cancer. Not by wearing it; many anti cancer drugs, such as cisplatin, pictured above, are made of platinum complexes. They work by twisting the DNA. The development of cisplatin improved the survival rate of testicular cancer from 15% to 80%.

PLATINUM AND HYDROGEN

A thin foil of platinum can be used to separate hydrogen from other gases. Hydrogen molecules split into the 2 hydrogen atoms on the surface of the platinum, and these atoms are the only thing small enough to travel through the bulk of it. This is useful for separating hydrogen from a gas stream. This property also  gives platinum a lot of potential use for fuel cells, but also has an impact on the cost of fuel cells and research into them.

Indeed, cost is one of the most important parameters in engineering. It’s the main reason something is or isn’t feasible. The large scale use of platinum to separate hydrogen from biological sources, for example, is in the realm of pipe dreams.

WHY IS IT SO EXPENSIVE?

Unfortunately, given it’s high demand, platinum is exceedingly rare. The average amount of platinum in the earths crust is 5 parts per billion. Only 245 tonnes were produced in 2010, compared with 800 tonnes of gold, and 21000 tonnes of silver.

However 76 tonnes of platinum is used in jewellery each year. That’s 31% of the platinum. Another 7% is used as investment in bullion reserves.

THE REAL PROBLEM

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Platinum  grills. Via Wikimedia Commons

Imagine if platinum, instead of being pretty shiny and easy to make into shapes, was ugly, smelly and brittle, like sulfur. Nobody in their right mind would make grills (pictured above) out of it. It’s trapped in a cycle that drives prices up; its desirability makes it even rarer, which makes it even more expensive and prestigious, and even more desirable as a status symbol. Speculators and investors win, but scientists and engineers lose. The price of platinum is often prohibitive even for lab scale experiments.

Should something be done about this? It’s not necessarily in the realm of science to define what “useful” is, but when vanity gets in the way of renewable energy and medicine, questions have to be asked. This was the case in World War 2. A decree in 1942, that was lifted in 1945, prohibited the manufacture of new platinum jewellery so it could be used for industry. Such dramatic measures aren’t be necessary, but this is definitely a case the market alone isn’t reaching the most efficient outcome.

It can just be frustrating to see enough platinum for 10 cars sitting on someone’s finger.


One Response to “Platinum’s Precious Problem”

  1. Ruth de Jager says:

    Wow, I have never properly known what platinum is. That’s kind of incredible that it’s so useful. I think there needs to be a platinum movement, where awareness is raised about it’s importance and the implications of it being a status symbol.