Zijn de dagen voor platina geteld ?........
Zal platina in de toekomst niet meer gebruikt worden in de katalysatoren van uitlaten ?.........
Scientists are narrowing in on an inexpensive substitute for platinum that can be used in hydrogen fuel cells.
Researchers from Brown University have created a cobalt-graphene catalyst that is performing better than platinum in some aspects.
Shouheng Sun and his students invented the new substance, a sheet of graphene coated in cobalt nanoparticles. The trick was getting the nanoparticles to form the exact shape desired, something Sun says is quite difficult. A complex process of centrifuges and sound waves was needed to get the surface of the substance to form the right shape.
The new catalyst actually performed more efficiently than platinum and was even more durable. However, it took longer for the reaction to get underway.
Despite the advances, Sun told Brown University that platinum is still the best catalyst.
"But it's very expensive and has a very limited supply, and that’s why you don’t see a lot of fuel cell use aside from a few special purposes," he said.
But Sun is optimistic that his substance, with a little more work, can replace platinum.
Hydrogen fuel cells are used in a number of specialized applications like buses, boats and electricity generation. Forklifts powered by fuel cells are popular since they can be operated indoors and give off no emissions. However, fuel cell technology has still proved too pricey for automobile use.
The current ask price for spot platinum is $1,674/oz. The metal has risen 16% this year, mostly off the labour unrest in South Africa.
By Michael Allan McCrae