Oxidation resistance of Ni/La0.7Sr0.3AlO3−δ catalyst for steam reforming of model aromatic hydrocarbon

Oxidative resistance of Ni catalysts supported on various oxides La0.7Sr0.3AlO3−δ, LaAlO3, and α-Al2O3 were investigated for hydrogen production by steam reforming of model aromatic hydrocarbons. Ni/α-Al2O3 lost its steam reforming activity by oxidation treatment. In contrast, Ni/La0.7Sr0.3AlO3−δ and Ni/LaAlO3 catalysts showed steam reforming activity even after the oxidation treatment. The XANES (X-ray absorption near-edge structure) spectra at Ni K-edge for Ni/La0.7Sr0.3AlO3−δ and Ni/α-Al2O3 after oxidation treatment revealed that the supported Ni on La0.7Sr0.3AlO3−δ and α-Al2O3 were oxidized completely. Although the mean particle size of Ni on Ni/α-Al2O3 increased by oxidation treatment or reduction treatment, Ni particles on Ni/La0.7Sr0.3AlO3−δ retained the fine structure after oxidation treatment or reduction treatment. Moreover, TPR (temperature programmed reduction) and XPS (X-ray photoelectron spectroscopy) measurements for elucidating the reducibility of Ni/La0.7Sr0.3AlO3−δ showed that the supported Ni on La0.7Sr0.3AlO3−δ was easily reduced even after the oxidation treatment.