Again with the aim of reducing scarce metal usage, the institution's Internal Combustion Engine laboratory has developed an extremely efficient and economic foam catalyst. Changing the form of the ceramic substrate has enabled the use of less of the noble metals palladium and rhodium in comparison to conventional catalysts. In collaboration with Empa's Solid-State Chemistry and Catalysis laboratory, the motor scientists are conducting research work on regenerative exhaust gas catalysts which employed perovskites instead of scarce metals. The former are multifunctional metal oxides which, because of their special crystal structure, are capable of transforming heat directly into electrical energy.
The recycling challenge
Despite all the doom and gloom, we will not have to do without scarce metals entirely. As Heinz Boeni, head of the Technology and Society laboratory, maintained there is of course a reserve of scarce metals to be found in end-of-life electrical and electronic products. While natural primary deposits are being used up, the anthropogenic secondary deposits created by man are increasing continuously. In a ton of natural ore as mined there is typically about 5 g of gold. In a ton of discarded mobile telephones, on the other hand, there is about 280 g, while the same weight of scrap PCBs contains as much as 1.4 kg of the precious metal! But recovering scarce metals is anything but easy. You can't just pull them out from electronic waste with a screwdriver and a hammer. The recovery process is at least as complex as the design and development of the old appliances themselves, recycling expert Christian Hagelken made clear. A large percentage of scarce metals are to be found in the form of very thin layers or mixed with other substances in the form of alloys, added Hagelken, whose employer, Umicore, is one of the
|Contact: Dr. Patrick Wger|
Swiss Federal Laboratories for Materials Science and Technology (EMPA)