Facile One-Step Hydrothermal Synthesis of Amine-Functionalized Carbon Spheres Supporting Ultrafine Palladium Nanoparticles for Highly Efficient Formic Acid Dehydrogenation

Abstract Efficient hydrogen release from liquid organic hydrogen carriers requires advanced heterogeneous catalysts. This study presents a one-step hydrothermal synthesis of amine-functionalized carbon spheres supporting ultrafine (1.89 nm) palladium nanoparticles (Pd NPs) for formic acid (FA) dehydrogenation. The resulting Pd@NH2–CS catalyst exhibits 100% H2 selectivity for FA dehydrogenation with sodium formate (SF) under optimal conditions (333 K, FA/SF = 1:6), delivering a remarkable initial turnover frequency (TOF) of 7300 h–1. Characterization results indicate that amine functionalization not only restricts the growth of Pd NPs but also establishes strong metal–support interactions (SMSI). The resulting electron-deficient Pd species not only play a crucial role in enhancing the catalytic activity but also enable the catalyst to maintain reasonable reusability over multiple cycles. Ultimately, this facile support engineering strategy offers a scalable approach for designing highly efficient carbon-based catalysts for sustainable energy applications.