Experimental and Kinetic Study of Selective Catalytic Reduction of NO with NH 3 over CuO/Al 2O 3/Cordierite Catalyst

Abstract

The CuO/γ-Al 2O 3/cordierite catalyst, after being sulfated by sulfur dioxide (SO 2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH 3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH 3 over CuO/γ-Al 2O 3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy E′ a of 94.01 kJ·mol −1 and the corresponding pre-exponential factor A′ of 3.39×10 8 cm 3·g −1·s −1 when NH 3 is excessive. However, when NH 3 is not enough, an Eley-Rideal kinetic model based on experimental data is derived with E a of 105.79 kJ·mol −1, the corresponding A of 2.94×10 9 cm 3·g −1·s −1, heat of adsorption Δ H ads of 87.90 kJ·mol −1 and the corresponding A ads of 9.24 cm 3·mol −1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reactor design and engineering scale-up.