FAPO and Fe-TUD-1: Promising catalysts for N2O mediated selective oxidation of propane?

Iron (2 wt%) was incorporated into the structure of microporous AlPO4-5 (FAPOcal) and the mesoporous materials TUD-1 and Al-TUD-1 (Fe-TUD-1 and Fe-Al-TUD-1). FAPOcal was also additionally modified by steaming (FAPOste). Compared to literature data on optimized Fe-ZSM-5, FAPOcal shows relatively low activity and comparable selectivities in N2O induced propane selective oxidation. Steaming reduces the performance of this AlPO4-5 based catalyst. Fe-TUD-1 and Fe-Al-TUD-1 are less active and selective than FAPOcal. However, the stability of the investigated systems is significantly better than reported for Fe-ZSM-5. This is explained by differences in surface chemistry: operando DRIFT studies show formation of carbonates and carboxylates on the surfaces of the FAPO and TUD-1 based catalysts, rather than coke. Reasons for the different behavior of the herein investigated catalysts as compared to Fe-ZSM-5 are discussed.