Effects of sulfur poisoning on physicochemical properties and performance of MnO2/AlNi-PILC for toluene catalytic combustion

AlNi pillared clay (AlNi-PILC) was synthesized firstly, and then MnO2 was supported via wetness impregnation from nitrate precursors. Sulphation was performed by in-situ decomposing ammonium sulfate with different concentrations over MnO2/AlNi-PILC. Catalysts before and after sulfur poisoning were characterized by XRD, N2 adsorption/desorption, HRTEM, XPS, H2-TPR and NH3-TPD. MnO2/AlNi-PILC exhibited high catalytic activity, allowing the complete toluene combustion. Structure of the catalyst was obviously damaged after sulfur poisoning. (001) crystal plane strength of AlNi-PILC was decreased significantly. Meanwhile, the specific surface area and pore volume reduced with increase of sulfate concentration. Sulfur species were readily formed on the surface of poisoned catalyst and deposited in the pore structure of AlNi-PILC, which resulted in significant impacts on the structural stability, acidity and the number of active species. These changes were responsible for the decreased catalytic performance.

Automated summary

AlNi-PILC catalyst was synthesized and supported with MnO2. The structure of the catalyst is damaged after sulfur poisoning, leading to a decrease in specific surface area and pore volume, which in turn results in decreased catalytic performance.