Highly efficient and reusable CeVO₄@Fe₃O₄/(Cr–Fe/Co) magnetic nanocatalyst for sustainable hydrogen generation from NaBH₄ hydrolysis

This study presents the hydrothermal synthesis of CeVO₄@Fe₃O₄/(Cr–Fe/Co) and its catalytic performance in NaBH₄ hydrolysis for hydrogen generation. Key parameters, including NaOH and NaBH₄ concentrations, catalyst amount, and reaction temperature, were systematically optimized. Comprehensive characterization via SEM, EDX, XRD, BET, and FTIR revealed the structural and surface properties of the catalyst. The optimized catalyst exhibited an outstanding hydrogen generation rate of 19.65 L g_metal ⁻¹ min⁻¹ at 30 °C with an activation energy of 34.43 kJ mol⁻¹. FE-SEM analysis indicated particle agglomeration with a size distribution of approximately 60–70 nm, whereas the BET data demonstrated a moderate surface area and pore diameter of 46.34 m² g⁻¹ and 38.97 nm, respectively. Kinetic analysis using the Langmuir–Hinshelwood model revealed a moderate turnover frequency (TOF) of 2114.47 mol _H2 mol _cat ⁻¹ h⁻¹. Thermodynamic parameters further supported the catalytic efficiency, with ΔS° = 0.0103 ± 0.01 kJ mol⁻¹ K⁻¹, ΔH_ads = 0.12 ± 0.01 kJ mol⁻¹, and ΔG°(30 °C) = −3.00 kJ mol⁻¹. Remarkably, the catalyst maintained moderate efficiency after five reuse cycles, emphasizing its industrial viability and long-term stability. These findings suggest that CeVO₄@Fe₃O₄/(Cr–Fe/Co) is a promising candidate for scalable hydrogen generation.