On thermal stability and catalytic reactivity of Zr-based metal-organic framework (UiO-67) encapsulated Pt catalysts

Pt nanoparticles (NPs, 0.5 wt.%) encapsulated in a zirconium-based metal-organic framework (UiO-67 MOF) were synthesized via a linker design method. Thermal behavior of Pt in UiO-67 composite materials was compared with UiO-67 using thermogravimetric and differential thermal analysis (TG-DTA). The results showed that Pt insertion can impair the thermal stability of bulk UiO-67, resulting in a ca. 14% drop in the critical temperature of the thermal decomposition. Temperature-programmed oxidation of materials showed that calcination at 450 K was essential to provide a clean framework. Temperature-programmed reduction of materials revealed that the chemisorption of H₂ on UiO-67 (at 323 K) was evidently enhanced owing to the incorporation of Pt NPs, thus making PtNP@UiO-67 suitable for hydrogenation reactions and hydrogen storage. PtNP@UiO-67 catalyst was evaluated by the oxidation and hydrogenation of 5-hydroxymethylfurfural in aqueous solutions at 363 K, showing improved activity and selectivity in hydrogenation reactions.