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The mechanisms involved in catalytic oxidation of CO by N2 O promoted by the AlVO3+ and AlVO4+ ions are evaluated using temperature-dependent rate constants and statistical modeling. Reactions were studied from 300-600 K using a selected ion flow tube (SIFT) apparatus, and the data compared to statistical modeling of proposed mechanisms previously identified by density functional theory (DFT) calculations. Reduction of N2 O by AlVO3+ was found to take place only by complexation to the Al site; however, attack on the V site also occurred and led to stable association complexes, reducing the overall efficiency of the reaction. As the AlVO3+ (N2 O) complex resulted from approach on the V site, it did not block the reactive Al site and was observed to further react with N2 O to form AlVO4+ (N2 O). The oxidation of CO by AlVO4+ was found to proceed solely by activation on the Al-O site; however, isomerization of complexes formed with CO initially complexed to the V site were found to add to the reactivity, especially at lower temperatures.

Rate coefficients kMN have been measured for a number of anion neutralization reactions with Ar+ and Kr+ over the temperature range 300–550 K. For the first time, the data set includes anions of radicals and other short-lived species. In the present paper, we review these results and make note of correlations with reduced mass, electron binding energy of the anion (equivalent to the electron affinity of the corresponding neutral), and temperature, and compare with expectations from absorbing sphere models. An intriguing result is that the data for diatomic anions neutralized by Ar+ and Kr+ have kMN values close to 3 × 10−8 cm3 s−1 at 300 K, a figure which is lower than those for all of the polyatomic anions at 300 K except for SF5− + Kr+. For the polyatomic anions studied here, neutralized by Ar+ and Kr+, the reduced mass dependence agrees with theory, on average, but we find a stronger temperature dependence of T−0.9 than expected from the theoretical E−0.5 energy dependence of the rate coefficient at th...