Effect of pseudo-boehmite structure on hydrothermal stability of γ-Al_2O_3

Aluminum oxide has been widely used as the support for industrial catalysts,and its hydrothermal stability plays a critical role in the catalyst lifetime.The effect of pseudo-boehmite structure on hydrothermal stability of γ-Al2O3 obtained from pseudo-boehmite after calcination at 800 ℃(heating rate 10 ℃·min-1)for 4 h was investigated.The structure of alumina before and after hydrothermal treatment was characterized by N2adsorption-desorption,SEM,XRD,FT-IR and NH3-TPD.The results showed that the hydrothermal stability of γ-Al2O3 was determined by the crystallity of pseudo-boehmite.The well crystallized γ-Al2O3 with fewer hydroxyl and weak acidity exhibited higher hydrothermal stability compared with poor crystallized one.