Nickel Catalysts Based on LaCeY Ternary Oxide Supports for Dry Methane Reforming

Abstract

The structure of 10%Ni/LaCeY(n)O_x catalysts containing different amounts of yttrium (0.5–10 mol %) and their catalytic activity in dry methane reforming (DMR) have been studied. The phase composition of the support and catalyst samples has been characterized using a set of physicochemical methods; the effect of yttrium introduction method on the formation of the active surface of the catalysts has been studied. Varying the yttrium content in the support, it has been found that 1 mol % is the optimum amount of the introduced additive to provide minimum changes in the initial conversions of the reactants (methane and CO₂) and the H₂/CO ratio at 650°C for 6 h as compared to the respective parameters of the unmodified catalyst. An increase in the modifier content to 10 mol % leads to an increase in the deactivation rate due to more vigorous carbon deposition and the formation of encapsulating carbon species (amorphous carbon and onion-like carbon). The Ni/LaCeY(1)O_x sample exhibiting the highest stability under DMR conditions is characterized by the dominant content of multiwalled carbon nanotubes with uncapped end Ni nanoparticles.