Ethylene epoxidation in low-temperature AC corona discharge over Ag catalyst: Effect of promoter

In this work, the epoxidation of ethylene using a low-temperature corona discharge system was investigated with various reported catalytically active catalysts: Ag/alpha-Al2O3, Cs-Ag/alpha-Al2O3, Cu-Ag/alpha-Al2O3, and Au-Ag/alpha-Al2O3. It was experimentally found that the investigated catalysts could improve the ethylene conversion and the ethylene oxide (EO) yield and selectivity for the corona discharge system, particularly 1 wt.% Cs-12.5 wt.% Ag/alpha-Al2O3 and 0.2 wt.% Au-12.5 wt.% Ag/alpha-Al2O3. The power consumption per EO molecule produced in the corona discharge system, combined with the superior bimetallic catalysts, was much lower than that of the sole corona discharge system and that of the corona discharge system combined with the monometallic Ag catalyst. (C) 2009 Elsevier B. V. All rights reserved.