Operando FTIR study of the photocatalytic reduction of CO₂ in the presence of water vapor over Pt/TiO₂: on the role of surface residual C-species

Benchmark TiO2 and Pt/TiO2 photocatalysts were investigated by performing operando FTIR spectroscopy to shed light on catalytic pathways influencing photoreduction of CO2 in the vapor phase. Through a combination of multivariate curve resolution and chemometric analyses, the carbonaceous surface impurities were identified to be carboxylates, and the mechanisms of their subsequent involvement in surface reactions were demonstrated.