Catalytic reduction of nitric oxide by carbon monoxide.

The reduction of nitric oxide by carbon monoxide, reaction (l), mediated by metal complexes has attracted great attention recently due to its relevance to the control of air pollution and the intrinsic interest in the mechanism of N20 and C02 formation. 1-7 While a number of catalyst systems for reaction (1) have been reported, only the RhIILRhI and the PdC12CuCI2. systems rapidly catalyse the reaction and have been investigated in detail. In addition to the catalysis of reaction (1), palladium-copper systems have been useful catalysts in many important reactions,4.8 but the analogous platinumcopper system has never found application in any catalytic reaction. We now report the use of K2PtC14-CuC12-CuC1 as a catalyst system for reaction (1). This system is not only much more active than those previously reported, but also reveals a catalytic mechanism different from the palladium-copper catalysed reactions.