Effect of La, Ce, Y and B addition on thermal stability of unsupported alumina membranes

Phase composition and pore structure of La, Ce, Y and B doped unsupported alumina membranes were investigated by means of X-ray diffraction and N2 adsorption. The role of La, Ce, Y and B addition in enhancing the thermal stability of alumina membranes is discussed. At temperatures ranging from 800 to 1000 °C, La and Y impregnation are more efficient than that of B and Ce to preserve the BET surface area and pore volume. The addition of La can partially stabilize the alumina up membranes to 1200 °C by the delay of phase transformation from γ- to α-Al2O3.