Operando FTIR study of Fe-MOR, Co-MOR, and Ni-MOR as catalysts for simultaneous abatement of NOx and N2O with CH4 in the presence of O-2. An insight on reaction pathway

摘要

Co-, Fe- or Ni-exchanged Na-MOR (Si/Al = 9.2) were prepared by ion-exchange method. The catalytic activity of Fe-MOR catalyst for the simultaneous selective catalytic reduction of NOx and N2O with CH4 in the presence of excess O-2 (SCRsim) and for the related reactions (SCRN2O, SCRNO, N2O decomposition, N2O decomposition in the presence of NO and CH4 combustion) was investigated and compared with that previously measured for Co-MOR and Ni-MOR. The evolution of the surface species on Co-, Fe- or Ni-MOR (tmi-MOR) in the presence of flowing reactant mixtures during the SCRNO and the SCRsim were investigated by operando FTIR experiments and compared with that previously studied during SCRN2O. The correlation between the results of both operando FTIR and catalytic activity study gave an insight into the active sites and the pathway of the simultaneous abatement in tmi-MOR catalysts.