The role of pathogens in biological conservation

A solid carrier for catalytic material is coated with a slurry composed of alumina hydrate (Al2O3.nH 2O) dried at 250 DEG DIFFERENCE 350 DEG C, colloidal silica and water. Said carrier, after drying, is immersed in an aqueous solution of aluminum nitrate (Al(NO3)3) containing a nitrate of barium, lanthanum or another rare earth element and then dried and fired.