Effect of La on the thermal stability of Pd/γ-Al2O3 catalytic membranes

Lanthanum-doped Pd/γ-Al2O3 and Pd/γ-Al2O3 membranes were prepared by sol-gel methods. The thermal stability of the unsupported Pd/γ-Al2O3 and La/Pd/γ-Al2O3 membranes was investigated with BET (including average pore size, pore volume and BET surface area), XRD, and DTA techniques. The average pore size of the Pd/γ-Al2O3 membranes increased sharply after sintering at temperatures higher than 1000°C. Addition of 3 mol% lanthanum can raise the temperature of the γ-Al2O3 toα-Al2O3 phase transformation significantly. This improves the thermal stability of the Pd/γ-Al2O3 catalytic membranes.