Effects of Different Poison Factors on the Deactivation and Characteristics of Catalysts
The activity of a commercial Pt-Pd catalyst for VOC decomposition and the effects of different poison factors on
the deactivation of catalysts were investigated. The characteristics of fresh and reacted catalysts at different reaction
conditions were also analyzed and compared. Experimental results showed that the conversion efficiency of C3H6by the
catalysts were all up to 97.6%when the reaction condition was at 200-400oCwithout SO2 gas. When the inflow gas contained
400ppm or 800ppmSO2, the conversion efficiency of C3H6significantly decreased to 72.4% and 11.9%, respectively. The
poisoning effect of SO2on the catalysts was more obvious at low temperature (200oC). When the reaction temperature
increased to over 300oC, the conversion efficiency of C3H6by the catalystswould increase up to 96%. From the BET, SEM,
EDS, and XRD analysis results, the major poisoning mechanismsof the catalyst were carbon deposition, sintering, and the
formation of metal sulfides.Moreover, the Taguchi Orthogonal Array method was utilized to evaluate the influences of
different poison factors and find the best operating conditions for the catalysts. The results showed that the influence of
different factors on the activity of catalysts flowed the sequence of reaction temperature, SO2concentration, and
C3H6concentration. The best reaction condition for the Pt-Pd catalyst was 400oC, 0ppm SO2, and 1000ppm C3H6, where the
conversion efficiency of C3H6was up to 99%.
Keywords: Catalyst, Deactivation, Poison Factor, Characteristic, Taguchi Orthogonal Array.