Adsorption and Reaction of Methanol Molecule on Nickel Cluster Ions, Ni_n⁺ (n = 3−11)

Abstract

The reactions of methanol on a size-selected nickel cluster ion, Ni n + (n = 3−11), were investigated at collision energies less than 1.0 eV in a beam-gas geometry. Dominant reactions were methanol chemisorption, demethanation, and carbide formation. The absolute cross sections of these different reactions were measured and found to change dramatically with the cluster size; the demethanation proceeds preferentially on Ni4 +, the carbide formation on Ni7,8 +, and the chemisorption on Ni6 +. A kinematic model explains the size-dependent characteristics that the chemisorption proceeds efficiently if the barrier height between the physisorbed and the chemisorbed states is low, and the demethanation and the carbide formation proceed otherwise. The rate of the carbide formation depends sensitively on an Ni−Ni distance of Ni n + so that it proceeds only on Ni7,8 +.

Detection of OH Stretching Mode of CH3OH Chemisorbed on Ni3+ and Ni4+ by Infrared Photodissociation Spectroscopy

“…11 The geometrical structure and the site of the chemisorbed CH 3 OH on Ni 4 + is almost the same as that of Ni 3 + as described above, but the electron density distributions of the Mulliken charges differ significantly. As shown in Figure 4, Ni 4 + (CH 3 OH) carries a higher negative charge on the O atom and positive charge on the H atom of the hydroxyl group than Ni 3 + (CH 3 OH) does.…”

Adsorption and dehydrogenation of ammonia on vanadium and niobium nitride cluster cations

“…The experimental apparatus used in the present study consists of a cluster ion source, a cooling cell, two quadrupole mass filters (QMFs), a reaction cell, and a detector, which are connected by octopole ion beam guides, and has been described in detail in our previous paper [30]. Briefly, bare metal cluster ions and their nitrides were produced by sputtering four separate metal targets (99.9% purity for vanadium, 99.8% for niobium) with accelerated 8.5-keV Xe + beams from the ion gun (CORDIS Ar25/35c, Rokion Ionenstrahl-Technologie) in the presence of a trace of nitrogen gas.…”

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

“…25 Clusters were produced by cosputtering four separate targets with accelerated xenon ion beams from the ion gun (CORDIS Ar25/35c, Rokion Ionenstrahl-Technologie). Here, three copper plates and one aluminum plate were used as targets.…”