Research on the Catalytic Hydrolysis of COS by Fe−Cu/AC Catalyst and Its Inactivation Mechanism at Low Temperature**

Abstract For removing carbonyl sulfide (COS) from industrial waste gas at low temperatures, the critical approach is to prepare an efficient and cheap catalyst. In this paper, Fe/Cu modified coal‐based activated carbon (AC) was prepared by co‐precipitation method and tested for the catalytic hydrolysis of carbonyl sulfide (COS) at low temperatures in a fixed‐bed reactor. The results showed that the best mole ratio of Fe/Cu was 1 : 1 and the best content of metal oxides was 50 %. BET, XRD, XPS, FTIR, and SEM investigated the structure and surface properties. COS was hydrolyzed on Fe 2 O 3 to produce H 2 S and CO 2 , and H 2 S reacted with CuO to have CuS. At the same time, H 2 S reacted with Fe 2 O 3 to produce FeS and elementary sulfur. Oxidized elemental sulfur was to form sulfuric acid, which responded with Fe 2 O 3 to form sulfates. The sulfates would be deposited on the catalysts’ surface and block the pore structure. Deactivation of metal oxides and blockage of pore structures were the main reason for catalyst deactivation.