Study of Ni and Pt catalysts supported on α-Al2O3 and ZrO2 applied in methane reforming with CO2

Ni and Pt catalysts supported on alpha-Al2O3, alpha-Al2O3-ZrO2 and ZrO2 were studied in the dry reforming of methane to produce synthesis gas. All catalytic systems presented well activity levels with TOF (s(-1)) values between 1 and 3, being Ni based catalysts more active than Pt based catalysts. The selectivity measured at 650 degrees C, expressed by the molar ratio H-2/CO reached values near to 1. Concerning stability, Pt/ZrO2, Pt/alpha-Al2O3-ZrO2 and Ni/alpha-Al2O3-ZrO2 systems clearly show lower deactivation levels than Ni/ZrO2 and Ni or Pt catalysts supported on alpha-Al2O3. The lowest deactivation levels observed in Ni and Pt supported on alpha-Al2O3-ZrO2, compared with Ni and Pt supported on alpha-Al2O3 can be explained by an inhibition of reactions leading to carbon deposition in systems having ZrO2. These results suggest that ZrO2 promotes the gasification of adsorbed intermediates, which are precursors of carbon formation and responsible for the main deactivation mechanism in dry reforming reaction. (c) 2006 Elsevier B.V. All rights reserved.