Glucose-Mediated Synthesis of Spherical Carbon Decorated with Gold Nanoparticles as Catalyst in a Hydrogen Generation Reaction

The growing environmental and economic impacts of carbon-based fuels have accelerated the search for sustainable alternatives, with hydrogen (H2) emerging as a clean and efficient energy carrier. Sodium borohydride (NaBH4) is a promising hydrogen storage compound, due to its high hydrogen content (10.6 wt%) and stability under ambient conditions. However, its hydrolysis with water proceeds slowly without an effective catalyst. In this study, gold nanoparticle-decorated spherical carbon (AuSC) composites were synthesized and evaluated as catalysts for NaBH4 hydrolysis. The spherical carbon support, prepared via a glucose-mediated route, provided a high-surface-area and conductive matrix that dispersed and stabilized Au nanoparticles, preventing agglomeration. Catalyst morphology and composition were characterized using XRD, TEM, SEM, and EDS analyses. The AuSC catalyst exhibited excellent catalytic activity, producing 21.8 mL of H2 at pH 7, 303 K, and 835 μmol NaBH4. The activation energy (Ea) was determined to be 51.6 kJ mol−1, consistent with a heterolytic B–H bond cleavage mechanism at the Au–C interface. The TON (2.82 × 104) and TOF (1.41 × 104 h−1) values confirmed high intrinsic catalytic efficiency. These results demonstrate that Au-decorated spherical carbon composites are efficient, stable, and promising catalysts for hydrogen generation from NaBH4 hydrolysis under mild conditions.