Syngas production via methane tri-reforming on Ni/La₂O₃-Al₂O₃ catalysts

Ni/La2O3-alpha Al2O3 catalysts were characterized and tested in the methane tri-reforming reaction. The catalysts were prepared by the combustion method, and characterized by nitrogen physisorption, SEM, XRD, and Rietveld refinement, H-2-TPR, and CO2-TPD. The metallic dispersion of Ni in the catalysts increased with the addition and increase of La2O3 amount. The reaction tests showed that the addition of La2O3, and the consequent increase in the metallic dispersion of Ni, influenced the catalytic results, favoring the selectivity towards H-2 production, leading to higher resistance to carbon deposition on the catalyst surface. However, there was a decrease in the selectivity towards H-2 and a higher rate of carbon deposition for catalysts with a higher additive content, having its maximum even with the increase in Ni dispersion, with the catalyst N10L alpha A. This result suggests that there was a limit for the La2O3 content, above which there would no longer be observed beneficial effects for the reforming process. The N2.5L alpha A catalyst showed the highest selectivity towards H-2 and the lowest carbon deposition rate among the catalysts.