Study on the Mechanism of SO2 Poisoning of MnOx/PG for Lower Temperature SCR by Simple Washing Regeneration

Manganese oxide-supported palygorskite (MnOx/PG) catalysts are considered highly efficient for low-temperature SCR of NOx. However, the MnOx/PG catalyst tends to be poisoned by SO2. The effect SO2 on activity SO2-pretreated poisoning under ammonia-free conditions was explored. It determined that considerably deactivated in absence ammonia and water-washed regeneration can completely recover catalyst. Based these results characterizations catalysts, a reasonable mechanism deactivation proposed this study. easily oxidized SO3 surface catalyst, leading formation polysulfuric acid, wrapping active component blocking micropores. is initially caused rather than deposition sulfate, which occurs later.