• Pd/CeO 2 catalysts prepared by DP and IW methods. • IW synthesis yields higher THF dehydrogenation activity. • Synthesis pH strongly modifies ceria support properties. • Acidic media promote spillover and Pd–Ce solid solution formation. This work demonstrates that the morphological and surface chemistry modifications induced on the ceria support during the preparation of Pd/CeO 2 catalysts play a decisive role in their performance for the dehydrogenation of tetrahydrofuran (THF), a key reaction for hydrogen chemical storage (THF/furan pair of potentially sustainable origin). The reaction was studied in a fixed-bed reactor at 200–300° C, 0.1 MPa, and WHSV = 2.1 h⁻ 1 , using catalysts with two Pd loadings (0.5 and 1 wt%). Two preparation methods, incipient wetness impregnation (IW) and deposition–precipitation (DP), were compared. The IW procedure leads to notable morphological and chemical modifications of the ceria surface, as revealed by N 2 physisorption (marked alterations in isotherm shape) and DRIFTS (increased hydroxyl concentration and modified THF adsorption modes), also affecting the nature of the metal crystallites through the incorporation of Ce in the crystalline structure. These changes promote hydrogen spillover, as evidenced by H 2 -TPD, which in turn results in more active and furan-selective catalysts, despite having similar palladium dispersion. Catalyst stability is also significantly higher for IW-prepared samples, suggesting that spillover contributes to mitigating the formation of carbonaceous deposits, identified as the main deactivation cause. Finally, the influence of temperature on the deactivation of the most active catalyst (1 wt% Pd, IW) was assessed, showing that operation within the 250–275 °C range enables very limited deactivation.
Prieto et al. (Sun,) studied this question.