Structural and textural evolution of Ni/γ-Al2O3 catalyst under hydrothermal conditions

The influence of hydrothermal treatment on the structural and textural properties of Ni/γ-Al2O3 catalysts is investigated by means of X-ray diffraction (XRD), H2-TPR, TG–DSC and N2 physisorption. After hydrothermally treated at 90–150 °C and 8–48 h, the γ-Al2O3 support transforms into its hydrated phase, boehmite [γ-AlO(OH)]. And the content of γ-AlO(OH) increases with the hydrothermal temperature and time increasing. Furthermore, the hydration of γ-Al2O3 support induces the aggregation of carried Ni crystallite and decreases the BET specific surface area and pore volume, and also reduces the interaction between Ni and γ-Al2O3 support. The above structural and textural changes further cause the hydrogenation activity decay of Ni/γ-Al2O3 catalyst.