Catalyst poisoning in the conversion of CO and N2O to CO2 and N2 on Pt4- in the gas phase

Pt-4-(-) catalyses the conversion of CO and N2O to CO2 and N-2 in the gas phase, as observed by Fourier transform ion cyclotron (FT-ICR) mass spectrometry. The partial pressures of CO and N2O determine the extent of poisoning and the turnover numbers that can be achieved. The catalytic conversion terminates as soon as two CO are adsorbed on the cluster. With N2O, the reactivity of Pt4O2- and Pt4O3- is reduced to 41% and 34% compared to Pt4O-, respectively, and with Pt4O4- this value is reduced to 1%. In contrast, Pt-4(+) shows no apparent catalytic activity. Density functional theory calculations of Pt-4(-) with CO and N2O adsorbates reveal significantly different stabilities of the reaction intermediates for the different charge states.