CO2 poisoning of the γ-alumina-catalyzed reaction of COS with SO2

The poisoning of γ-alumina by CO2 has been shown to suppress the catalytic reaction, 2COS + SO2⇌(3/x)Sx+ 2CO2. Using infra-red spectroscopic evidence, a mechanism of reaction was postulated in which SO2 is adsorbed on hydroxyl sites and COS is adsorbed on aluminum ion sites. The latter sites become blocked through irreversible chemisorption of CO2. The postulated mechanism appears to explain other experimental observations.