Syngas production by partial oxidation of methane over Pt/CeZrO2/Al2O3 catalysts

Abstract In this study, we evaluated the effect of ceria–zirconia content on the performance of Pt/ x %CeZrO 2 /Al 2 O 3 ( x  = 0–40 wt.%) during partial oxidation of methane. X-ray diffraction results indicated that, for samples containing 10 and 20 wt.% of CeZrO 2 , there was the formation of a homogeneous solid solution between ceria and zirconia. On the other hand, for Pt/30%CeZrO 2 /Al 2 O 3 , there was the formation of a ceria rich phase and a zirconia rich phase whereas a ceria rich phase and an isolated zirconia phase were detected for Pt/40%CeZrO 2 /Al 2 O 3 . Catalytic tests showed that Pt/Al 2 O 3 exhibited a significant deactivation, while Pt/10%CeZrO 2 /Al 2 O 3 and Pt/20%CeZrO 2 /Al 2 O 3 practically did not loose their activity after 24 h. A deactivation was detected for Pt/30%CeZrO 2 /Al 2 O 3 and Pt/40%CeZrO 2 /Al 2 O 3 . The higher stability of the Pt/10%CeZrO 2 /Al 2 O 3 and Pt/20%CeZrO 2 /Al 2 O 3 catalysts was attributed to the high reducibility and consequently the high oxygen mobility of the homogeneous solid solution formed, which promoted the mechanism of carbon removal from the metallic particle.