Hydrogen production from oxidative reforming of methane on Ni/γ-M2O3 catalysts: Effect of support promotion with La, La-Ce and La-Zr

摘要

Ni/Al2O3 catalysts promoted by adding La2O3, La2O3-CeO2 and La2O3-ZrO2 were investigated on oxidative and steam reforming aiming the hydrogen production. The samples were characterized by surface area estimation (BET), XRD, TPR, TPD-H2 and XANES. Analysis of TEM and TPO was performed as complementary characterization for catalysts after reaction. The oxidative steam reforming of methane at temperatures above 500 °C reveals that all the promoted catalysts presented better activities than the unpromoted. Below 500 °C, the catalysts presented deactivation due to metallic nickel species oxidation and the TEM analysis of Ni/Al and Ni/La-Al catalysts revealed that the lanthanum addition led to a decrease in the Ni species particle size and also to a better active phase dispersion. The results suggest that below 500 °C the activity may be related to differences in the metallic area values, although the Ni/La2O3-Al2O3 catalysts have shown a different behavior.