Redoxreaktionen des CO/N₂O‐Systems, katalysiert durch das bimetallische Oxidclusterpaar AlVO₃⁺/AlVO₄⁺

Abstract

Autoabgase entgiften: Die katalytische Umwandlung von N2O und CO in N2 und CO2 ist eine wichtige Aufgabe, und das Verständnis der genauen Abläufe ist dabei von großer Bedeutung. Die Untersuchung dieser Reaktion unter thermalisierten Bedingungen in der Gasphase mit dem bimetallischen Oxidclusterpaar AlVO3+/AlVO4+ als Katalysator, bei dem sich das reaktive M‐Ot.‐Zentrum am Hauptgruppenelement Al befindet (siehe Bild; Al pink), liefert hier neue, hilfreiche Befunde.

Doping Effects in Cluster‐Mediated Bond Activation

“…[45] In the presence of CO (Figure 3 Oxide Clusters in the Gas Phase Angewandte is added, the reverse reaction occurs.Both processes are clean and proceed with efficiencies of 59 %and 65 %relative to the collision rate,respectively.Inprinciple,the turnover number of the catalytic cycle is infinite. [45] In the presence of CO (Figure 3 Oxide Clusters in the Gas Phase Angewandte is added, the reverse reaction occurs.Both processes are clean and proceed with efficiencies of 59 %and 65 %relative to the collision rate,respectively.Inprinciple,the turnover number of the catalytic cycle is infinite.…”

“…[45] As shown in Figure 4, the transition state TS1 of the uncatalyzed reaction is much too high in energy to play ar ole under ambient conditions.I nc ontrast, the catalytic conversion, which takes place at the doublet ground state of [AlVO 4 ]C + ,commences by abarrier-free binding of the carbon atom of CO to the radical oxygen atom of the Al À O t C (O t = terminal oxygen atom) moiety to generate intermediate 4. [45] As shown in Figure 4, the transition state TS1 of the uncatalyzed reaction is much too high in energy to play ar ole under ambient conditions.I nc ontrast, the catalytic conversion, which takes place at the doublet ground state of [AlVO 4 ]C + ,commences by abarrier-free binding of the carbon atom of CO to the radical oxygen atom of the Al À O t C (O t = terminal oxygen atom) moiety to generate intermediate 4.…”

“…Thecouple [AlVO 3 ]C + /[AlVO 4 ]C + serves as an example for probing the catalytic redox features and determining the active site of aheteronuclear metal-oxide cluster in the roomtemperature oxidation of CO by N 2 O. [45] In the presence of CO (Figure 3 Oxide Clusters in the Gas Phase Angewandte is added, the reverse reaction occurs.Both processes are clean and proceed with efficiencies of 59 %and 65 %relative to the collision rate,respectively.Inprinciple,the turnover number of the catalytic cycle is infinite.…”

“…The reaction [O t V(m-O) 2 AlO t ]C + + CO! [O t V-(m-O)2 Al]C + + CO 2 (red line) (adapted from Ref [45]2 Al]C + + CO 2 (red line) (adapted from Ref [45]…”

On the Origin of the Surprisingly Sluggish Redox Reaction of the N2O/CO Couple Mediated by [Y2O2]+. and [YAlO2]+. Cluster Ions in the Gas Phase

“…However, compared with the rather straightforward reduction of [AlVO 4 ] +. by CO,8 the potential-energy surface (PES) for the couple 5 /CO is mechanistically more subtle with regard to the liberation of CO 2 from the encounter complex 6 .…”