Mechanism of Adsorptive Removal of tert-Butanethiol under Ambient Conditions with Silver Nitrate Supported on Silica and Silica−Alumina

Vapor-phase adsorptive removal of tert -butanethiol (TBT) over silver nitrate supported on silica (AgSi) and silica−alumina (AgSiAl) is tested under ambient conditions. Saturation uptakes on AgSi and AgSiAl are close to that on Ag-exchanged Y zeolite, which was shown to have high sulfur capacity in the literature. The structural analyses by XRD, TEM, Ag K-edge XANES/ EXAFS, and in situ UV−vis show that the reaction of Ag + species on these samples with TBT yields AgSH species, Ag 2 S monomer, Ag 4 S 2 cluster, and Ag 2 S particles. Dynamic changes in adsorbed intermediates and the silver sulfides were followed by in situ FTIR and in situ UV−vis, and the following reaction mechanism is presented: (1) reaction of Ag + with TBT to produce butenes and AgSH species; (2) reaction of the two AgSH to produce Ag 2 S monomer and H 2 S; (3) aggregation of Ag 2 S monomer to (Ag 2 S) n clusters and Ag 2 S particle.