Au/TiO2 photocatalysts were used in ethanol oxidative dehydrogenation. Catalysts at gold loading ranging between 0.5-2 wt.% were synthesized by photodeposition (using different deposition times: 15 and 120 min) over an ownprepared TiO2 by sol-gel method. For reference purposes, a commercial 1 wt.% Au/TiO2 catalyst (AUROliteTM, Strem Chemicals) was also tested. Photocatalytic reactions were carried out in a gas-solid photocatalytic fluidized bed reactor. Catalytic activity depends strongly both on Au loading and on the material properties, such as particle size and distribution of metal on titania surface. Acetaldehyde was the main reaction product, with ethylene, crotonaldehyde and CO2 as by-products. An important improvement of TiO2 photoactivity was achieved for the catalyst with 0.5 wt.% gold prepared with 120 min deposition time. For an ethanol inlet concentration of 0.2 vol% at 60 °C, the maximum conversion and acetaldehyde selectivity were 82% and 95%, respectively. These values are considerably higher than those obtained over pristine TiO2 and over the commercial catalyst.
Oxidative Dehydrogenation of Ethanol over Au/TiO2 Photocatalysts
SANNINO, Diana;VAIANO, VINCENZO;CIAMBELLI, Paolo;
2012-01-01
Abstract
Au/TiO2 photocatalysts were used in ethanol oxidative dehydrogenation. Catalysts at gold loading ranging between 0.5-2 wt.% were synthesized by photodeposition (using different deposition times: 15 and 120 min) over an ownprepared TiO2 by sol-gel method. For reference purposes, a commercial 1 wt.% Au/TiO2 catalyst (AUROliteTM, Strem Chemicals) was also tested. Photocatalytic reactions were carried out in a gas-solid photocatalytic fluidized bed reactor. Catalytic activity depends strongly both on Au loading and on the material properties, such as particle size and distribution of metal on titania surface. Acetaldehyde was the main reaction product, with ethylene, crotonaldehyde and CO2 as by-products. An important improvement of TiO2 photoactivity was achieved for the catalyst with 0.5 wt.% gold prepared with 120 min deposition time. For an ethanol inlet concentration of 0.2 vol% at 60 °C, the maximum conversion and acetaldehyde selectivity were 82% and 95%, respectively. These values are considerably higher than those obtained over pristine TiO2 and over the commercial catalyst.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
