Dark catalytic reduction of CO 2 over Prussian blue-deposited TiO 2 and the photo-reactivation of the catalyst

Abstract

The catalytic reduction of CO 2 has been performed over Prussian blue-deposited TiO 2 particles, and the products were methanol, ethanol, acetaldehyde and acetone with a negligibly small amount of methane. The deposition of Prussian blue (PB) onto TiO 2 particles was accomplished under the irradiation of light, and on this occasion PB was further reduced to ES (reduced form of PB). The hydrogenation Of CO 2 taking place in dark was caused by the reaction with active hydrogen atoms generated in the redox reaction consisting of the oxidation of ES to PB and the reduction of H 2O. The deactivated catalyst was restored in KCl aqueous solution under the illumination of light by photo-rereducing PB to ES.