Sustainable Synthesis of CoFe2O4/Fe2O3 Catalyst for Hydrogen Generation from Sodium Borohydride Hydrolysis

Abstract

Hydrogen has been explored as a greener alternative for greenhouse gas emissions reduction. Sodium borohydride (NaBH4) is a favorable hydrogen carrier due to its high hydrogen content, safe handling, and rapid hydrogen release. This work presents a novel synthesis of the catalyst CoFe2O4/Fe2O3 using nanocellulose fibers (TCNF) as reactive templates for metal adsorption and subsequent calcination. The resulting material was tested for H2 production from basic NaBH4 aqueous solutions (10–55 °C). The catalyst’s composition is 74.8 wt% CoFe2O4, 25 wt% Fe2O3, and 0.2 wt% Fe2(SO4)3 with agglomerated spheroidal particles (15–20 nm) and homogeneous Fe and Co distribution. The catalyst produced 1785 mL of H2 in 15 min at 25 °C (50 mg catalyst, 4.0% NaBH4, and 2.5 wt% NaOH), close to the stoichiometric maximum (2086 mL). The maximum H2 generation rate (HGR) reached 3.55 L min−1 gcat−1 at 40 °C. Activation energies were determined using empirical (38.4 ± 5.3 kJ mol−1) and Langmuir–Hinshelwood (L–H) models (42.2 ± 5.8 kJ mol−1), consistent with values for other Co-ferrite catalysts. Kinetic data fitted better to the L–H model, suggesting that boron complex adsorption precedes H2 evolution.