Abstract: Acidification by HCl or H2SO4 was applied for modifying bentonite. The Au catalysts supported on acid-activated bentonite had been prepared by the methods of aqueous impregnation, deposition-precipitation and cationic absorption. CO oxidation was used as a probe reaction to characterize the catalytic performance. The samples were characterized by BET, XRD and TEM. The BET results showed that the surface area and pore volume had a substantial improvement. The results of CO oxidation showed that a higher catalyst activity was achieved by Au supported on H2SO4 acidified bentontie. The calculation result by XRD indicated that the Au particles supported on H2SO4 acidified bentontie had smaller size. Small Au particles could be obtained by the method of cationic absorption. Au catalysts with higher catalytic activity could be obtained by the conditions of adsorption for 48 h, calcination at 450 ℃ and H2 reduction at 150 ℃.

Key words: acid-activated bentontie, Au catalysts, CO oxidation