fig4

Figure 4. Catalytic mechanism. (A) MS analysis of H₂ generated in the Pt/PN-CeO₂/H(D)₂O/benzaldehyde systems; (B) Distributions of reactants and products of the AWS of benzaldehyde catalyzed by Pt/PN-CeO₂ at intervals during a period of 10 h; (C) H₂ evolution profile with a time from the reaction mixture; (D) The illustration of benzaldehyde oxidation, benzyl alcohol oxidation, and the disproportionation of aldehyde over the Pt/PN-CeO₂ catalysts. Reaction conditions: PhCHO (1 mmol), H₂O/D₂O (0.5 mL), 1, 4-dioxane (1 mL), NaOH (2.5 mmol), catalysts (30 mg), 180 °C and 10 h. MS: Mass spectrometry; AWS: aldehyde-water shift.