Honeycomb CuO/Al2O3/Cordierite Catalyst for Selective Catalytic Reduction of NO by NH3-Effect of Al2O3 Coating

Al2O3-coated cordierite has been widely used as a catalyst’s support. In this work, three Al2O3 precursors or alumina sols are studied to understand the effect of type, viscosity, and grain size of the sols and Cl− on properties and SCR activities of honeycomb CuO/Al2O3/cordierite catalysts. X-ray diffraction (XRD), N2 adsorption, scanning electron microscopy and energy dispersive X-ray (SEM-EDX) techniques are used for analyses. Results show that the viscosity and average grain size of the sol have significant influences on the amount and stability of the Al2O3 coating. The sol synthesized from AlCl3 and aluminum is the best among the three sols in terms of less coating cycle, stability of the coating, and selective catalytic reduction (SCR) activity. Cl1− introduced in preparation must be washed out because it deactivates the SCR activity.