Palladium Supported on Porous Chitosan–Graphene Oxide Aerogels as Highly Efficient Catalysts for Hydrogen Generation from Formate

• Main Authors: Aicha Anouar, Nadia Katir, Abdelkrim El Kadib, Ana Primo, Hermenegildo García
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Molecules
• Subjects: liquid hydrogen carriers; formate as hydrogen carrier; catalyst for hydrogen generation; palladium as catalyst for hydrogen generation; chitosan–graphene oxide as catalyst support
• Online Access: https://www.mdpi.com/1420-3049/24/18/3290

Adsorption of Pd(NH₃)₄²⁺ in preformed chitosan−graphene oxide (CS-GO) beads and their subsequent reduction with NaBH₄ afford well-dispersed, high dispersion (~21%) of uniformly sized Pd nanoparticles (~1.7 nm). The resulting Pd/CS-GO exhibits interesting catalytic activity for hydrogen generation by ammonium formate decomposition. The optimal GO proportion of 7 wt% allows reaching, at 60 °C, a turnover frequency above 2200 h^−1—being outstanding among the highest values reported for this process to date. Interestingly, no formation of CO or CH₄ was detected. The catalyst did not leach, although it underwent gradual deactivation, probably caused by the increase in the Pd average size that became over 3 nm after three uses. Our results are relevant in the context of efficient on-board hydrogen generation from liquid organic hydrogen carriers in transportation.