Catalytic oxidation of CO with N2O on isolated copper cluster anions.

A catalytic redox reaction involving N2O and CO on size-selected copper cluster anions, Cun(-), was investigated in the gas phase using a guided ion-beam tandem mass spectrometer. When Cun(-) is exposed to a mixture of N2O and CO, CunO(-) is produced via the decomposition of N2O. Increase of the CO partial pressure results in the reproduction of Cun(-) and decrease of CunO(-) through the oxidation of CO. The present results demonstrate that a full catalytic cycle for the reaction, N2O + CO → N2 + CO2, takes place on copper cluster anions. Furthermore, in the investigations of the elementary reactions of Cun(-) + N2O and CunO(-) + CO, we found that the catalytic oxidation of CO with N2O on Cun(-) proceeds most efficiently at n = 7 in the size range of n = 5-16.