Metal–oxide interactions modulating the activity of active oxygen species on atomically dispersed silver catalysts

Abstract

The activity of active oxygen species on supported Ag atoms can be effectively modulated by metal–support interactions using different oxide supports. The strong interaction between Ag and Al₂O₃ with more electrons transferred from Ag to Al₂O₃ leads to the formation of more Ag–O₂⁻ (superoxide) species, responsible for the selective oxidation of ethylene to ethylene oxide. The relatively weak interaction between Ag and SiO₂ induces the generation of Ag–O (atomic oxygen) and Ag–O₂²⁻ (peroxide) species, which are more active for complete oxidation of CO and ethylene to CO₂. This work is of significance for deep understanding of active surface species in atomically dispersed metal catalysts.