Photocatalytic reduction of CO2 with H2O on various titanium oxide photocatalysts

Abstract

The specific features of the photocatalytic reduction of CO₂ with H₂O on various types of active titanium oxide catalysts are reviewed. UV-light irradiation of the bulk TiO₂ powders in the presence of CO₂ and H₂O at room temperature under heterogeneous gas-solid conditions produced CH₄ as the major product, while the predominant formations of CH₃OH as well as CH₄ were observed on the highly dispersed titanium oxide moiety anchored on zeolites and mesoporous silica materials. The CH₃OH formation is originated from the unique properties of the charge transfer excited state, i.e., (Ti³⁺–O⁻)* of the tetrahedrally-coordinated titanium oxide species within the silica frameworks.