Highly Regioselective Oxybromination in an Aqueous System Using SBA‐15 Supported Sulfated Zirconia Catalyst

SBA‐15 supported sulfated zirconia (SZ) catalysts were employed in many acid‐catalysis of reactions under mild condition because it is a strong solid acid with various Lewis and Brønsted acid sites. An oxybromination of aromatic substrates using hydrogen peroxide and ammonium bromide in the aqueous phase under mild temperature and near‐neutral pH condition over SZ was achieved. A good to excellent para‐selectivity was observed. The mesoporous silica SBA‐15 supported SZ possessed higher catalytic activity than self‐supported SZ because of larger surface area and pore size. The effect of the calcinations temperature was also investigated. The good catalytic performance of the SZ/SBA‐15 materials was attributed to high degree of dispersion of sulfate groups to give sulfated silica‐zirconia of (1) very good redox property and (2) high strength and high density of acid sites. The SZ/SBA‐15 catalyst may be re‐used several times without substantial loss of activity.