Deactivation pathways of Co- and Pt,Co-Mordenites used for the SCR

L. GUTIERREZ, M.A. ULLA, E.A. LOMBARDO, F. LÓNYI, J. VALYON

Philadelphia, Pennsylvania, USA

Congreso; 19th North American Catalysis Society Meeting; 2005

North American Catalysis Society

The addition of Pt to Co-mordenite enhances N2 production, but both the Co and Pt,Co-mordenites deactivate with time-on-stream. The nature of the deactivation process is still unclear. Recently, Pieterse et al. pointed out several causes of deactivation of Pd,Cozeolites used for the same purpose. Boix et al. studied the stability of both Co- and Pt,Co-ZSM5 and reported that after use Co3O4 becomes clearly visible in the former sample while in the latter only Co2+ at exchange sites and highly dispersed CoxOy species are present after use. In this work, we have studied the stability of Co and Pt,Co-mordenites in long-term runs at 500ºC with feedstreams containing 10% water. The characterization of fresh and used catalysts was carried out using FTIR to monitor the fate of adsorbed species formed from N2 or pyridine. Raman spectroscopy was used to detect the presence of cobalt oxides while the lattice stability was checked through XRD and pore volume data obtained from N2 adsorption at 77 K.