Stable Au catalysts for selective hydrogenation of acetylene in ethylene

This study investigates the first Au catalysts prepared by photocatalysis process for selective hydrogenation reaction. The photocatalysis process is more straightforward than the encapsulation methods to prepare Au catalysts with small particles. Both 1% and 5%Au/C-TiO2 catalysts were tested for selective hydrogenation of acetylene in ethylene with H2/C2H2 ratios of 2/1, 5/1 and 10/1. With H2/C2H2 ratio of 5/1, both 1% and 5%Au/C-TiO2 catalysts show maximum yields of acetylene conversion to ethylene. Especially, the yield of 1%Au/C-TiO2, after reduction at 250 °C, reaches above 80% at temperatures from 200 °C to 275 °C. Most significantly 1%Au/C-TiO2, after reduction at 250 °C with H2/C2H2 ratio of 5/1, is not only active and selective but also stable for selective hydrogenation of acetylene in ethylene. It maintains ∼100% acetylene conversion with ∼80% selectivity to ethylene after 12 h at 225 °C.