Oxidation–reduction of Ni/Al2O3 steam reforming catalysts promoted with Mo Original Research Article

Model Ni/Al2O3 catalysts promoted with different amounts of molybdenum were examined in order to explain a strong increase of the resistance to coking in the steam reforming of hydrocarbons. The properties of catalysts were investigated after various treatment conditions in the water/hydrogen mixtures by means of XRD, XPS, temperature-programmed and gravimetric methods. The studies evidenced the enhancement of the surface or bulk oxidation processes in the presence of Mo promoter. The obtained results indicated that on the surface of Ni–Mo catalysts in the steam reforming reaction the presence of larger number of oxygen adatoms may facilitate transformation of hydrocarbon species, restrain formation of inactive carbon deposit.