Computational insights into promoting effects of alkali metals, Re, and Cl for silver catalysts of ethylene epoxidation

Abstract The effects of Re oxospecies, Cl, and alkali metal (AM = Li, Na, K, Rb, Cs) promoters for silver catalysts of ethylene epoxidation are considered using the DFT approach. The formation of Ag-bound AMReOx surface complexes that affect the catalyst performance is demonstrated. The interplays between silver, alkali metals, and anionic promoters are discussed. The Li-based systems mostly affect the catalyst activity while other alkali metals additionally affect the selectivity towards ethylene oxide in a varying extent. The Rb dopant shows potential as a Cs substitute or co-promoter. The facile composition–performance descriptor comprising the correlation of the substrate binding energy and charge over oxygen atom is proposed. The results obtained can be used in the applied designing of Ag-based epoxidation catalysts.