(292d) Controlling Catalysts’ Structure and Methane Oxidation Performance Using Flame Spray Pyrolysis
AIChE Annual Meeting
2022 Annual Meeting
Catalysis and Reaction Engineering Division
Catalyst Design, Synthesis, and Characterization V: Novel Catalysts
Tuesday, November 15, 2022 - 1:24pm to 1:42pm
Oxygen mobility and Pd speciation are essential factors that affect methane oxidation activity. X-ray diffraction and Raman spectroscopy show that the formation of single-phase and oxygen vacancy amount in the support can be adjusted by Ce:Zr element ratio and FSP synthesis conditions. A low oxygen flow rate can promote oxygen vacancy formation in solid solution catalysts. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) indicates that the formation of Pd2+ species can be favored by the oxidizing environment in the flame induced by high oxygen flow rate and low amount of fuel in the precursor. Besides, the samples with high oxygen vacancy amount can cause a strong metal-support interaction and speed up the re-oxidation from Pd0 to Pd2+, which eventually promotes the Pd2+ species formation. Activity tests show that solid solution catalysts with a higher oxygen vacancy amount and more Pd2+ species could perform better. The T50 of the best sample reaches 400 ÂºC. Our results indicate that catalystsâ structure, including oxygen vacancy amount and Pd speciation, can be adjusted by the FSP synthesis, speeding up the functional material discovery process.