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摘要:
An innovative simplified modification method for red mud had been proposed, which enabled its utilization as an active Fe 2 O 3 -rich component for catalytic oxidation of toluene. The Box-Behnken design, based on Response Surface Methodology (RSM), was employed to optimize the modification of bauxite residue using oxalic acid combined with UV irradiation. Based on the experimental conditions, the optimal conditions for three independent parameters were determined: acid leaching time (2 hours), UV irradiation time (1 hour), and acid dosage (150 ml),which was in order to enhance the maximum catalytic efficiency of toluene at 300 degrees C. Under the optimal preparation conditions provided by the Box-Behnken design, the catalytic efficiency of toluene at 300 degrees C could reach 99.2%. In comparison to the acid -modified mud (MRM) and untreated bauxite residue (RM), the aluminum refinery residue modified with oxalic acid -assisted UV irradiation (MRM-UV) exhibited the formation of oxalate sub -iron precipitates, resulting in significantly lower catalytic temperatures (238 degrees C). Furthermore, through XRF, XRD, XPS, O 2- TPD, and H 2 -TPD analysis, it was discovered that a large amount of iron oxide and calcium oxide formed CaO+Fe 2 O 3 -> Ca 2 Fe 2 O 5 , strengthening the interaction between iron and calcium, augmenting the migration rate of lattice oxygen from the bulk phase to the surface. Consequently, T 50 were reduced by 20.9% and 31.8% when compared to MRM and RM. Moreover, the CO 2 selectivity of MRM-UV increased from 8.6% to 70.5% compared to RM at 300 degrees C. Using in situ DRIFTS, the reaction pathway of toluene on MRM-UV was identified as benzyl alcohol -> benzaldehyde or benzoyl -> benzoate -> maleic anhydride -> CO 2 and H 2 O. The process refinement reduced VOCs emissions and promoted sustainable waste management by combining oxalic acid with catalytically active red mud.
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来源 :
CATALYSIS TODAY
ISSN: 0920-5861
年份: 2024
卷: 433
5 . 3 0 0
JCR@2022
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