(521x) Density Functional Theory Study for Ethylene Production from CO2 on Cu/TiO2 Photocatalyst

The use of photocatalysts to convert ethylene to CO₂ is a promising method for sustainable CO₂ utilization. Cu is a vital element in photocatalytic CO₂ reduction using a heterogeneous catalyst, as it enhances the activity of TiO₂-based photocatalysts for CO₂ reduction. The difference in reduced Ti state can generate Cu⁺/Cu²⁺ through the interaction between the TiO₂ surface and Cu particles. This study aims to investigate the formation of carbon products through this difference and the role of Cu particles. To determine the mechanism change according to the charge of Cu at the beginning, density functional theory (DFT) calculations were performed to compare the energies of C₁ and C₂ product formation through CO₂ reduction. Side reaction preferences were compared based on mechanism preference and energy comparison of each mechanism. The RDS was identified by the activation energy results. Bader charge analysis was performed to explain the initial Cu⁺ and Cu²⁺ modeling. By identifying the role of Cu particles on TiO₂, a highly efficient photocatalyst can be used depending on the Cu charge, and a more efficient reaction pathway can be presented by controlling side reactions in the C₁ and C₂ product mechanisms.