Core-shell doping of cerium oxide with (Cr-Fe/Co)-B catalyst for enhanced hydrogen evolution in borohydride hydrolysis systems: performance and catalytic efficiency

Herein, we successfully synthesized a CeO2@(Cr-Fe/Co)-B catalyst for hydrogen generation via NaBH4 and KBH4 hydrolysis using a hydrothermal method. To investigate the catalytic activity and hydrogen generation rate (HGR) of the catalyst, various parameters, including the catalyst amount, temperature, reusability, and the concentrations of MOH and MBH4 (M = Na, K), were tested. The catalyst was comprehensively characterized using FE-SEM, EDX, XRD, BET, TEM, XPS, and FTIR. The CeO2@(Cr-Fe/Co)-B catalyst exhibited a non-uniform, highly agglomerated, spherical morphology. TEM analysis revealed a core-shell structure with CeO2 as the core and an 8-16 nm (Cr-Fe/Co)-B shell. BET analysis confirmed the mesoporous nature of the catalyst, with a 27.19 nm pore diameter enabling efficient diffusion and interaction during reactions. The catalyst demonstrated excellent performance, achieving an HGR of 13.05 L g(metal)(-)(1) min(-)(1) for NaBH4 hydrolysis with an activation energy of 18.59 kJ mol(-)(1) and 9.06 L g(metal)(-)(1) min(-)(1) for KBH4 hydrolysis with an activation energy of 30.02 kJ mol(-)(1). Five consecutive experiments were conducted to evaluate the reusability of CeO2@(Cr-Fe/Co)-B for catalytic hydrolysis of NaBH4 and KBH4.