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Adsorption and Reactivity of CO 2 on Potassium‐Covered Re(001)
Author(s) -
Zhao Wei,
Chacham Ilan,
Vackart Yahel,
Asscher Micha
Publication year - 1998
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.199800046
Subject(s) - chemistry , potassium , adsorption , work function , desorption , quenching (fluorescence) , dissociation (chemistry) , inorganic chemistry , carbon dioxide , analytical chemistry (journal) , thermal desorption spectroscopy , metal , fluorescence , organic chemistry , physics , quantum mechanics
The interaction of CO 2 with potassium‐covered Re(001) has been investigated. This system has been studied by means of work function (Δϕ), optical second harmonic generation (SHG), and temperature‐programmed desorption (TPD) measurements. Strong electronic interaction between carbon dioxide and potassium is observed upon adsorption at 90 K. This is indicated by a rapid quenching of the SHG signal of K following postadsorption of CO 2 , with a quenching cross section of 70 Å 2 . Work function change measurements are consistent with such interaction, evidenced by an undepolarization effect, namely, further decrease of the work function upon CO 2 adsorption, below the minimum obtained by pure potassium. In the presence of potassium, the dissociation probability of 0.5 ML adsorbed carbon dioxide increases from 0.5 on the clean metal surface to 0.85 on 1 ML potassium‐covered Re(001), information obtained from TPD measurements following heating to 1250 K. It is concluded that a K–CO 2 surface compound is formed upon adsorption at 95 K on the potassium‐covered surface.