Platinum Metals Review - Volume 18, Issue 1, 1974

Catalysts containing ruthenium are used to reduce nitric oxide in automobile exhaust emissions but volatile oxides formed under transient oxidising conditions during operation can severely affect them. However, basic oxides such as alkaline earths or rare earths can stabilise the ruthenium by forming ruthenates, which have little tendency to volatilise. The ruthenates are synthesised either before the catalyst is made or in position on the catalyst support, which may be monolithic or pelleted.

With new techniques of crystal growth new problems have been encountered with the platinum apparatus used in crystal production. Some of these difficulties are discussed in this paper, including attack by bismuth oxide, Bi2O3, and dissolution of the platinum in the leaching acids, together with methods of prolonging the life of platinum crucibles.

Certain partially oxidised transition metal complexes possess structural and electronic properties which suggest that they are capable of development as one-dimensional metallic conductors. Studies of such platinum complexes have proved the most encouraging and may lead to the development of high temperature superconductors.

Very pure metals of the actinide, lanthanide and alkaline earth series can be prepared from their oxides by coupled reduction by hydrogen in the presence of platinum group metals. During the process the platinum group metals form intermetallic phases with the metals from the oxides. These phases are decomposed to yield the pure metals in gaseous form and the platinum group metals in solid form. The pure gaseous metals condense to produce pure solid specimens.