Hydrogen Production from Formic Acid Decomposition Promoted by Gold Nanoparticles Supported on a Porous Polymer Matrix

Formic acid (FA) is considered one of the most promising carriers of clean and safe dihydrogen. This study highlights the potential of using poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) as a support for AuNPs to produce H2 through formic acid dehydrogenation (FAD). The developed synthesis method allows for precise control over the gold content by completely encapsulating AuNPs (4–6 nm) within the PPO matrix, ensuring a uniform distribution of nanoparticles with an active cubic morphology. In an aqueous solution (or a water/DMAc mixture), the catalyst exhibited high activity, generating H2 without producing CO, underscoring its high selectivity for dehydrogenation. At 105 °C, the catalyst showed a TOF of 360 molFA·molAu–1·h–1 and an activation energy of 39.3 ± 2.6 kJ·mol–1. By optimizing the formic acid concentration and gold loading, the system achieved an impressive TOF of 600 molFA·molAu–1·h–1, comparable to the best values reported in the literature. Notably, the AuNPs-PPO system facilitates the FAD reaction without requiring additional bases or modified supports. The reaction order of 0.81 ± 0.04 with respect to FA concentration indicates the rapid diffusion of the reagent within the polymer matrix without limiting its reactivity. Lastly, the AuNPs-PPO catalytic system has been demonstrated to be reusable.