Reversible deactivation of TiO2 in CS2 conversion associated with Claus reaction

CS2 destruction is an important reaction in industrial Claus process. A reversible deactivation over titania in CS2 conversion has been found in this laboratory. This deactivation is closely related to the presence of Claus reaction. The key intermediate species of Claus reaction is thiosulfate anion, S2O32−, which further reacts with Bronsted acid of titania to form surface polythionates. The long S chain of the latter would shield the active centers responsible for CS2 conversion and causes the deactivation, while these polythionates can be easily destroyed by heating at 330 °C, which is finally accompanied by a recovery of catalytic activity in CS2 conversion.

A reversible deactivation over titania in CS2 conversion has been found in this laboratory. This deactivation is closely related to the presence of Claus reaction. The key intermediate species of Claus reaction is thiosulfate anion, S2O32−, which further reacts with Bronsted acid of titania to form surface polythionates. The long S chain of the latter would shield the active centers responsible for CS2 conversion.Figure optionsDownload as PowerPoint slide