The selective catalytic reduction of NO with propane over Ni loaded on H-USY in the presence of excess oxygen

The abatement of NO with propane in the presence of excess oxygen has been investigated on several kinds of commercial USY (Ultra Stable Y zeolite) in the Na-form (Na-USY) and H-form (H-USY) or wet impregnated to various extents with Ni ions (Ni/USY) catalysts. Experimental results indicated that Ni/H-USY loaded with 15% Ni showed comparatively better catalytic activity for Selective Catalytic Reduction (SCR) of NO with propane and it can suppress effectively the formation of N₂O and CO. The reaction order was also studied and the reactants effect was discussed on the catalyst of Ni/USY. The new catalyst samples were characterised by measurements of BET, X-Ray Diffraction (XRD), H₂-Temperature Programmed Reduction (TPR), Scanning Electron Microscopy (SEM) and IR for pyridine adsorption and NO adsorption. The chemical analysis indicates that NiO is distributed on the external surface of the zeolite particles. A synergistic effect between Ni²⁺ and Brønsted acids is responsible for the SCR of NO on Ni/H-USY. Nitrate compounds of Ni²⁺ formed on Ni/USY after NO adsorption favour the reduction of NO with propane.