모노리스 NH₃-SCR 반응기 내에서의 NH₃ 흡·탈착 특성에 대한 연구

Transient kinetics of NH₃ adsorption/desorption and of SCR (selective catalytic reduction) of NO with NH₃ were studied over vanadium based catalysts, such as V₂O_5/TiO₂ and V₂O_5-WO₃/TiO₂. In the present catalytic reaction process, NO adsorption is neglected while NH₃ is strongly chemisorbed on the catalytic surface. Accordingly. it is ruled out the possibility of a reaction between strongly adsorbed NH₃ and NO species in line with the hypothesis of an Eley-Rideal mechanism. The present kinetic model assumes; (1) non-activated NH₃ adsorption, (2) Temkin-type NH₃ coverage dependence of the desorption energy, (3) non-linear dependence of the SCR reaction rate on the NH₃ surface coverage. Thus, the surface heterogeneity for adsorption/desorption of NH₃ is taken into account in this model. The present study extends the pure chemical kinetic model based on a powdered-phase catalytic system to the chemico-physical one applicable to a realistic monolith reactor.