Comparison of Adsorption Probabilities of O₂ and CO on Copper Cluster Cations and Anions

Abstract

Reactions of size-selected copper cluster cations and anions, Cu(n)(±), with O(2) and CO have been systematically investigated under single collision conditions by using a tandem-mass spectrometer. In the reactions of Cu(n)(±) (n = 3-25) with O(2), oxidation of the cluster is prominently observed with and without releasing Cu atoms at the collision energy of 0.2 eV. The reactivity of Cu(n)(+) is governed to some extent by the electronic shell structure; the relatively small reaction cross sections observed at n = 9 and 21 correspond to the electronic shell closings, and those at odd sizes in n ≤ 16 match with the clusters having no unpaired electron. On the other hand, the reactivity of Cu(n)(-) exhibits no remarkable decrease by the electronic shell closings and the even-numbered electrons. These behaviors may be due to an influence of the electron detachment of the reaction intermediate, Cu(n)O(2)(-). Both the cations and anions show the dominant formation of Cu(n-1)O(2)(±) in n ≤ 16 and Cu(n)O(2)(±) in n ≥ 17 in the experimental time window. By contrast, Cu(n)(-) (n = 3-11) do not react with CO at the collision energy of 0.2 eV, while Cu(n)(+) (n = 3-19) adsorb CO though the cross sections are relatively small. The difference in the reactivity between the charge states can be understood in terms of the frontier orbitals of the Cu cluster and O(2) or CO.

Stability of Aluminum-Doped Copper Cluster Cations and Their Reactivity toward NO and O2

“…The intensity of Cu n + drops significantly beyond the sizes of n = 3, 9, and 21, which is essentially consistent with the observation in our previous study where four Cu targets were used. 21 For Cu n Al + , similar stepwise drops in the intensity are observed beyond n = 6 and 18 ( Figure 1b). Additionally, even−odd alternations appear clearly for both Cu n + and Cu n Al + clusters, where the clusters with an odd number of atoms are more abundant than the adjacent even-numbered ones.…”

Infrared Multiple Photon Dissociation Spectroscopy of Hydrated Cobalt Anions Doped with Carbon Dioxide CoCO2(H2O)n−, n=1–10, in the C−O Stretch Region

“…Vibrational spectroscopy is a powerful method for structural analysis in the gas phase . Vibrational spectra of Co n + (CH 3 OH) 3 ( n= 1–3) were measured by IR photodissociation spectroscopy . Anionic cobalt clusters doped with methanol, ethanol, or propanol molecules were probed by IR spectroscopy in the O−H stretch region .…”

DENSITY FUNCTIONAL CALCULATIONS ON SPECTRUM AND ELECTRONIC PROPERTIES OFWNCO(N= 1 ~ 6) CLUSTERS

“…In the past few years, gas molecules adsorbed on transition metal clusters has been widely investigated owing to their unique physical and chemical properties, [1][2][3][4][5][6][7][8][9][10] such as extreme hardness, high melting point, chemical inertness, interesting catalytic behavior, etc. Carbon monoxide is one of the most important gases which participate in catalytic processes in heterogeneous phase.…”