Enhanced hydrogen release from sodium borohydride using a bio-based N-Chit@SiO2 catalyst in mixed solvents

Abstract

This work focuses on tuning catalyst-solvent interfacial interactions through a bio-inorganic hybrid design rather than introducing new nitrogen precursors. A bio-derived self-nitrogen-enriched chitosan/silica hybrid catalyst (N-Chit@SiO2) is developed for hydrogen production via the solvolytic decomposition of NaBH4. Self-doped nitrogen functionalities provide electron-donating active sites, while SiO2 improves structural stability, dispersion, and reactant accessibility. Catalytic activity was evaluated in methanol and methanol-propylene glycol mixed solvents under alkaline-free static conditions, highlighting a practical reaction environment. Under optimized conditions, the mixed solvent system achieves a hydrogen generation rate of 32,775 mL min-1 gcat-1 at 30 degrees C, with a low apparent activation energy of 19.88 kJ mol-1, confirming efficient reaction kinetics. The catalyst maintains over 53% activity after multiple cycles, demonstrating moderate durability under repeated use conditions. These results reveal a simple bio-derived catalyst design enabling efficient and stable hydrogen generation without external alkaline additives., sustainable, and efficient strategy for hydrogen generation under additive-free conditions.