Role of lattice oxygen migration in Ni-based catalyst for natural gas conversion

We explore a new concept for controlling the anticoking performance over ni ckel-based catalysts for methane conversion into synthesis gas at 1173 K. W hen CaTiO3 type oxide exhibiting ionic and electronic mixed conduction intr oduced by the partial substitution of titanium(IV) site by iron(III) ion is used as a support material, coke formation over the catalyst during methan e conversion with air or carbon dioxide is strongly dependent on the iron(I II) ion content. From the relationship between the amount of carbon deposit ed on the catalyst and the mixed conduction in the support oxide, it is fou nd that the self-migration of lattice oxygen inside the support regulating the balance between the oxide ionic and electronic conductivities plays an important role to prevent accumulation of deposited carbon over the catalys ts. (C) 2001 The Electrochemical Society.