Hydrothermal ethanol conversion on Ag, Cu, Au/TiO2

The effect UV irradiation and silver, copper, and gold ions (M z+) supported on titania (anatase) have on the activity of M/TiO 2 samples in ethanol conversion at 150-400°C is examined. After UV irradiation, the yields of acetaldehyde and ethylene increase for TiO 2 and Ag/TiO2 samples, while the activity of Cu 2+/TiO2 decreases. The activation energy of ethanol dehydration declines in the order TiO2 > Au3+ > Cu2+ > Ag+ and correlates linearly with a reduction in the radius of M z+ in crystal. The number of acidic sites on a M/TiO2 surface titrated via pyridine adsorption grows upon the introduction of M. Unlike Cu2+/TiO2, these sites are not activated after the irradiation of TiO2, Ag+/TiO 2, and Au3+/TiO2. According to IR spectral data on adsorbed pyridine, all samples contain Lewis and Brönsted acidic sites. © 2014 Pleiades Publishing, Ltd.