Liquid phase selective hydrogenation of phthalic anhydride to phthalide over titania supported gold catalysts

Au/TiO2 catalysts with different gold loadings were prepared by deposition–precipitation method and used for the liquid phase hydrogenation of phthalic anhydride. All the studied Au/TiO2 catalysts exhibited excellent activity with high selectivity (>92%) to phthalide under mild reaction conditions (180 °C and 3.0 MPa H2). Specially, catalysts with 2–3 wt.% gold loading were highly active and selective for the formation of phthalide. When reused, the catalyst showed a certain deactivation, but still was highly selective to phthalide. The deactivation was attributed to the leaching of gold, collapse of the pore structure and accumulation of organic species on the surface.