Effect of calcination temperatures on the properties of α-Al_2O_3 carrier

α-Al2O3 carriers were prepared from a green alumina carrier by calcination at different temperatures.The carriers were characterized by XRD,N2adsorption-desorption,mercury porosimetry and SEM.The effects of calcination temperatures on the physical properties of α-Al2O3 carrier such as surface area,pore structure,and microstructure were systematically studied.The results showed that the calcination temperature of T ℃(basic calcination temperature) was the critical temperature at which the carrier was completely transformed into crystalline α-Al2O3.The carrier calcined at the critical point T ℃ possessed the maximum surface area,1.11 a m2·g-1(a was a reference value).With the increase of calcination temperature,the surface area decreased and the pore size increased.In addition,the crystalline of alumina carrier became more structured.The calcination temperatures of the carriers supplied by different manufacturers need to be redetermined in order to obtain suitable surface area,pore size distribution,and stable properties of α-Al2O3 carrier and the catalysts.