Exploring the effect of the reaction conditions on the mechanism of the photocatalytic reduction of CO₂ in the vapor phase over Pt/TiO₂: an operando FTIR study

Abstract

The utilization of photocatalysis for CO2 conversion into solar fuels holds significant promise for advancing clean energy solutions. However, there are still many uncertainties regarding the surface mechanisms of the...

Evidence on C–C Coupling to Acetate as Key Reaction Intermediate in Photocatalytic Reduction of CO2 over Pt/TiO2

“…In absence of CO 2 , there is a clear depletion of C-species within the defined spectral region (1800−1200 cm −1 ) over successive irradiation cycles (Figure S3A), which is in agreement with the depletion of carbon impurities from the surface. 14 On the other hand, when CO 2 is introduced, C-species are clearly replenished on the surface (Figure S3B). For more information about the surface evolution, please refer to ref 14.…”

“…The advantages of operating in periodic irradiation conditions have been previously detailed in our earlier study. 14 In this study, we utilize the spectra gathered during cycle/periodical irradiations, and we process them through a chemometric approach. Briefly, initial examination of the spectra (Figure S3) shows clear distinctions during the process of photoactivation under argon (Ar + H 2 O) and in the presence of carbon dioxide (CO 2 + H 2 O).…”

“…9,30,31 The formation of defects, possibly during the photodeposition procedure adopted in this study, could facilitate the reduction of surface-adsorbed carbonates due to electron transfer and stabilize the formation of carboxylates on the fresh catalyst surface. 14 However, further specific analyses are needed to confirm the presence of defects on the Pt/ TiO 2 −10 min sample.…”

“…13 Our previous study demonstrated that carbon residues significantly impact CO 2 photocatalytic reduction, accounting for up to 40% of methane yields. 14 Given the low yields of CO 2 conversion, it is crucial to distinguish between products from residual-carbon impurities and those from the reduction of CO 2 to better understand the underlying reaction mechanisms.…”

“…These residues, originating from catalyst preparation or organic compound adsorption, can contribute to reaction products, complicating the attribution of products solely to CO 2 reduction . Our previous study demonstrated that carbon residues significantly impact CO 2 photocatalytic reduction, accounting for up to 40% of methane yields . Given the low yields of CO 2 conversion, it is crucial to distinguish between products from residual-carbon impurities and those from the reduction of CO 2 to better understand the underlying reaction mechanisms.…”