Structure and activity of Ni/La0.7Sr0.3AlO3−δ catalyst for hydrogen production by steam reforming of toluene

• Hydrogen production by catalytic toluene steam reforming was investigated.
• Ni/La0.7Sr0.3AlO3−δ showed high catalytic activity and coke resistance for the reaction.
• Ni/La0.7Sr0.3AlO3−δ catalysts calcined at various temperatures were compared.
• Interaction between lattice oxygen and Ni particle was important for coke suppression.
• Lattice oxygen mobility was affected by the perimeter of Ni particle.

We investigated catalytic steam reforming of aromatic hydrocarbon using toluene as a model compound. Ni/La0.7Sr0.3AlO3−δ catalyst showed high catalytic activity and low coke formation. Although the lattice oxygen in a perovskite-type support plays an important role for oxidizing CHx and coke precursor, the role of interaction between Ni and the support has not been clarified. In this study, Ni/La0.7Sr0.3AlO3−δ catalyst calcined at various temperatures (1073, 1173, 1273 and 1373 K) was prepared and used to elucidate the effect of Ni particle size on the lattice oxygen mobility. The Ni particle size increased concomitantly with increased calcination temperature, and the C1 yield decreased from 72.9 to 15.5%. Enhancement of lattice oxygen mobility by the decrease of Ni particle size was observed by transient response tests using H218O over Ni/La0.7Sr0.3AlO3−δ calcined at various temperatures. The interface between Ni and perovskite support played an important role for oxidizing coke precursor by lattice oxygen.

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