Ruthenium/cobalt binary oxides supported on hollow alumina microspheres as highly efficient catalyst for vinyl chloride oxidation

Alumina hollow microspheres (Al2O3-hms) were synthesized and used to support metal oxide and binary metal oxide particles to prepare three catalysts, designated as RuOx/Al2O3-hms, CoOx/Al2O3-hms and RuCoOx/Al2O3-hms. Their catalytic properties in vinyl chloride oxidation were investigated and found to follow this order: RuCoOx/Al2O3-hms > RuOx/Al2O3-hms > CoOx/Al2O3-hms. In comparison with a commercial Al2O3 support, the Al2O3-hms provide a higher specific surface area and unique hollow spherical morphology, benefiting for uniform distribution of catalyst particles. It was also found that the strong metal-support interaction between metal nanoparticles and Al2O3-hms has significant effects on the low-temperature reducibility, the surface oxygen abundance and mobility, giving rise to different oxidation activities. The Al2O3-hms supported metal catalysts remained relatively high catalytic activity after consecutive catalytic runs and high-temperature annealing. The anti-sintering ability enhancement of metal particles was attributed to the stabilization and metalsupport interaction effects with Al2O3-hms.