Novel metal-modified ZSM-5 formulations as catalysts for the simultaneous reduction of NO and CO emissions from the regenerator of an FCC unit

A series of metal modified Cu/ZSM-5 catalytic formulations were evaluated as FCC catalytic additives for the in situ reduction of NO_x formed in the regenerator of a FCC unit. Utilization of CO promoters was considered as the base case for the evaluation of additives' performance. All Cu/ZSM-5 additives reduced NO emissions, while a CeO₂-promoted Cu/ZSM-5 additive showed the optimum deNOx performance. The Cu/ZSM5 additives were inefficient for CO oxidation and thus were also evaluated in the presence of a CO promoter, which lowered CO emissions but inhibited deNOx catalytic ability. Only the optimum CeO₂-Cu/ZSM-5 additive achieved a simultaneous reduction of NO and CO emissions. To enhance additives' ability for CO oxidation small amounts of Rh were added in their formulation and managed to achieve a combined NO reduction and CO oxidation in the absence of a CO promoter. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).