CO adsorption on supported and promoted Ag epoxidation catalysts

Adsorption of 1,3-butadiene on supported and promoted silver catalysts

“…12, reversibly adsorbed BD was the dominant species during exposure to BD, and no EpB was detected. Similar to the Cs-promoted catalyst, after a 30-min purge a carboxylate compound remained to give bands at 1588 and 1394 cm −1 and a 1643-cm −1 band was also detected, which is attributed to trace amounts of water [27].…”

“…This was used as the background reference in the fast Fourier transform analysis of all the subsequent interferograms recorded for that particular catalyst. As before, the spectra in absorbance units or K-M units were very similar, but we prefer to show the former because negative changes in the spectrum are also observable [27]. Afterward, the adsorbate was flowed through the catalyst bed in a He carrier gas (or isotopes were introduced to the evacuated cell) for 30 min and IR scans were taken after 30 min.…”

“…Details regarding the preparation and surface characterization of these supported silver catalysts have been given elsewhere [27]. The unpromoted catalyst used in this study is designated as UNP-II.…”

“…The prefixes CsN and CsCl indicate whether CsNO 3 or CsCl was the precursor Cs compound, and the number in parentheses indicates the analyzed Cs content in ppm as shown in Table 1. The properties of the catalysts are also given elsewhere [27]. In addition to these catalysts, experiments were performed with the pure α-Al 2 O 3 support (Norton Corp., SA 5562, 0.78 m 2 /g).…”

“…The samples were subjected to either a low temperature (LT) reduction at 473 K or a high temperature (HT) reduction of 673 K, and the surface was left in either a reduced or an O-covered state, as described in Table 2. Details of the diffuse reflectance FTIR system and the standard procedures employed to record spectra have been described in detail elsewhere [27]. Briefly, after loading the catalyst sample into the DRIFTS cell, the cell was purged overnight with He.…”