Detection and quantification of steady-state ethylene oxide formation over an Ag(111) single crystal

Identification of Adsorbed Species and Surface Chemical State on Ag(111) in the Presence of Ethylene and Oxygen Studied with Infrared and X-ray Spectroscopies

“…We also observed a very slight but steady increase in the m/z = 43 peak, which was attributed to EtO in similar gas-leaking experiments performed by other authors (Figure 4) [8]. We should note here that the same authors later suggested that the m/z = 43 peak could also be produced by acetaldehyde (AcH), which is a full oxidation product [48]. They suggested to use the intensity ratio of m/z = 43 and m/z = 42 peak to distinguish EtO from AcH [48], which is not possible in the present study due to very low signal-to-noise ratio of m/z = 42.…”

“…We should note here that the same authors later suggested that the m/z = 43 peak could also be produced by acetaldehyde (AcH), which is a full oxidation product [48]. They suggested to use the intensity ratio of m/z = 43 and m/z = 42 peak to distinguish EtO from AcH [48], which is not possible in the present study due to very low signal-to-noise ratio of m/z = 42. Based on Figure 4, we can confirm that the Ag(111) surface is active, at least for the full oxidation reaction, in the conditions chosen for this spectroscopy study.…”

The Selective Species in Ethylene Epoxidation on Silver

“…1 eV apparent activation energy for desorption from a first order Redhead analysis 11 -is consistent with previous measurements of an Ag(111) surface active in EO production during TPR 11 . It should be noted however, that m/z=29 is not unique to EO due to cross-sensitivities with 13 CO, H2 13 C= 12 CH2, and AcH 34 . We were able to eliminate the former two possibilities by confirming C2H3O (m/z=43) desorbs at the same temperature ( Figure 4) and can rule out AcH because it is converted entirely to CO2 in the presence of the 4 × 4 -O phase 12 .…”

“…(m/z=44 amu) or the m/z=29 amu fragment often assigned to a CHO fragment from EO 10,11,34 was observed in QMS. This inactivity is consistent with reports that, alone, the oxygen species with a BE of ca.…”

Towards Cardiolite‐Inspired Carbon Monoxide Releasing Molecules – Reactivity of d4, d5 Rhenium and d6 Manganese Carb­onyl Complexes with Isocyanide Ligands

“…Detection of EtO under the conditions of the steady‐state STM experiment by QMS was a massive problem because of the small surface of the single crystal, the extremely low reaction probability of the ethylene molecules, and cross sensitivities of the EtO mass fragments with byproducts, in particular CO 2 , and with ethylene. We have performed extensive experiments with a test reactor to identify conditions under which EtO could be safely detected 10. The method finally obtained uses switches between low and high temperatures to subtract a background signal and the m / z =43 molecular fragment for detection of EtO.…”