The effect of different atmosphere treatments on the performance of Ni/Nb–Al2O3 catalysts for methane steam reforming

Methane steam reforming is currently the most widely used hydrogen production reaction in industry today. Ni/Nb–Al 2 O 3 catalysts were prepared by treatment under H 2 , N 2, and air atmosphere prior to reduction and applied for methane steam reforming reaction at low temperature (400–600 °C). The hydrogen-treated catalysts increased catalytic activity, with 55.74% methane conversion at S/C = 2, GSVH of 14400 mL g −1 h −1 and 550 °C. The H 2 atmosphere treatment enhanced the Ni–Nb interaction and the formation of stable, tiny, homogeneous Ni particles (6 nm), contributing to good activity and stability. In contrast, the catalysts treated with nitrogen and air showed weaker interactions between Ni and Nb species, whereas the added Nb covered the active sites, which caused the decrease in activity. Meanwhile, carbon accumulation was also observed. This work is informative for preserving small nano-sized nickel particles to enhance catalytic performance. • Ni/Nb–Al 2 O 3 catalyst treated with H 2 showed higher activity at 400–600 °C. • Highest carbon build-up on N 2 -treated catalyst and least on H 2 -treated catalyst. • Strong Ni–Nb interaction reduces Ni 0 particle size (<7 nm). • H 2 treatment prevented carbon deposition.