Design of SrTiO3-based catalysts for photocatalytic CO2 reduction

Abstract

Herein, the preparation of SrTiO₃-based catalysts (i.e., NiO/support, Au-support and Au–NiO/support, where the supports were SrTiO₃ and SrTiO₃–SrCO₃) for photocatalytic CO₂ reduction considering strategic design principles is presented. The samples were comprehensively analyzed via complementary methods, such as SEM-EDX, XRD, nitrogen sorption, XPS and UV-vis (DRS), in situ EPR and in situ DRIFTS. The CO₂ photoreduction activity of the samples was assessed in a high-purity gas-phase photoreactor under batch conditions. The investigations highlighted that the reaction pathway (i.e., selective H₂ and C₂H₆ production vs. CH₄) can be influenced by the modification of the electronic properties (i.e., Fermi level alignment), the interaction between Au NPs and oxygen vacancies (i.e., in situ EPR) and the enhanced charge separation in the presence of SrCO₃. The participation of the structural carbonates in the reaction in association with the functionality of the components is discussed.