Promotion of Ni/H-BEA by Fe for NOx Reduction with Propane in a Lean-Burn Condition

The effect of iron addition to Ni/H-BRA on selective catalytic reduction of NOx with propane (C3H8-SCR) was investigated under a lean-burn condition. The addition of iron significantly lowered the optimum reaction temperature of Ni/H-BEA from 623 to 573 K. The 3Ni-1Fe/H-BEA catalyst had the highest activity among samples with different bimetal loading. NOx conversion of 100% was obtained at 573 K. Oxygen played an important role in activating NO and propane during the C3H8-SCR reaction. NOx conversion increased as the C3H8/NO molar ratio increased. A complete conversion of NOx was achieved with C3H8/NO = 1.25 at 573 K. The catalytic activity was inhibited slightly at a low SO2 concentration (100 ppm) but decreased dramatically at a high SO2 concentration (600 ppm) over different catalysts. The introduction of 10% water also exhibited a negative impact on the reduction of NOx. The catalytic activity of Ni-Fe/H-BEA represented only a slight drop in the presence of 100 ppm SO2 and 10% H2O. The addition of iron to Ni/H-BRA notably improved the tolerance of SO2 and H2O.