Size-Specific, Dissociative Activation of Carbon Dioxide by Cobalt Cluster Anions

作者：Yanagimachi Akimaro; Koyasu Kiichirou; Valdivielso David Yubero; Gewinner Sandy; Schoellkopf Wieland; Fielicke Andre; Tsukuda Tatsuya

来源：Journal of Physical Chemistry C, 2016, 120(26): 14209-14215.

DOI：10.1021/acs.jpcc.6b04360

The reaction of cobalt cluster anions Co-n(-) (3 <= n <= 17) with CO2 was studied experimentally and theoretically to explore the size-specific activation mode of CO2 by Co-n(-). Mass spectrometric measurements revealed that the reactivity depends strongly on cluster size: the reactivity emerges abruptly at n = 7, peaks at n = 8-10, and then gradually decreases with increasing n. Infrared multiple photon dissociation spectra of ConCO2- exhibit a single peak at similar to 1870 cm(-1), similarly to the previously reported spectra of ConCO-. Density functional theory calculations for Co7CO2- as an example revealed that the dissociative adsorption ofCO(2) into CO and O is energetically more favorable than nondissociative adsorption. The infrared spectra calculated for dissociated isomers Co-7(CO)O- reproduced the experimental results, whereas those for nondissociated isomers Co7CO2- did not. The photoelectron spectra of ConCO2- were shifted dramatically toward higher energies relative to those of Co-n(-), suggesting electron transfer from Co-n(-) to the CO and O ligands. These results indicate that the CO2 molecule adsorbs dissociatively on Co-n(-), in sharp contrast to its nondissociative adsorption onto the Co monomer anion.

• 出版日期2016-7-7