Optimal hydrocarbon selection for catalytic N2O reduction over iron-containing ZSM-5 zeolite
M. A. G. Hevia, J. Pérez-Ramírez
Environ. Sci. Technol. 2008, 42, 8896-8900
Abstract: The selective catalytic reduction of N2O over steam-activated FeZSM-5 zeolite has been investigated at 473−823 K using C1−C3 hydrocarbons (methane, ethane, ethene, ethyne, propane, and propyne). The assessment of the hydrocarbons for nitrous oxide abatement is discussed according to different criteria: (i) de-N2O activity and operation temperature, (ii) hydrocarbon utilization, that is, the selectivity to react with N2O in O2 excess, (iii) emission of CO and CO2, (iv) sensitivity to NO and NH3, and (v) cost. Alkanes are generally more effective reducing agents than unsaturated hydrocarbons. In particular, alkynes require higher temperature to activate N2O and are unselective because of their proneness to react with O2. Ethane is an optimal reductant, featuring a high de-N2O activity, high selectivity, and compared to methane, a lower degree of inhibition by NO.