Hydrogen production from oxidative reforming of methane on Ni/γ-Al2O3 catalysts: Effect of support promotion with La, La–Ce and La–Zr

Abstract

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.