Silica-doped TiO2 as support of gallium oxide for dehydrogenation of ethane with CO2

Dehydrogenation of ethane to ethylene in the presence or absence of CO 2 over silica-doped TiO 2 supported Ga 2 O 3 catalysts was investigated. The silica doping of TiO 2 support greatly improved the dehydrogenation activity in the absence of CO 2 , which can be ascribed to the increased acid sites. The initial activity in the presence of CO 2 decreased after the silica doping, due to the reduction in reverse water-gas shift ability. However, the selectivity as well as the stability increased, resulting in higher steady ethylene yield. A dynamic process consisting of alternative oxidative dehydrogenation/regeneration cycles by gasifying the carbon deposit with air for 10 min after each cycle of 6 h reaction was also performed and relatively stable ethane conversion ~30% and ethylene yield ~25% can be achieved. The different catalytic behaviors are probably associated with the different state of gallium species, caused by the different interaction between the Ga 2 O 3 and support.