Real-time tunable hydrogen generation from hydrolysis of borohydrides using 3D magnetic catalysts

Abstract

Hydrolysis of borohydrides is a promising method for the hydrogen supply of high-energy-density fuel cells. Realization of on-demand hydrogen generation is critical and challenging for efficient utilization of hydrogen. Herein, we proposed a novel strategy to realize the real-time dynamic tunability of the hydrogen generation rate of the reaction for the first time. To realize this strategy, an applicable 3D catalyst is developed by depositing catalytic materials on readily available polymer foams through a simple electroless plating method, showing remarkable catalytic activity (12 560 mL min⁻¹ g_catalyst⁻¹, 10 470 mL min⁻¹ g_{overall structure}⁻¹) and durability toward the hydrolysis of NaBH₄. Due to its multiple advantages, valuable regulation of the H₂ production rate was realized by simply adjusting the contact area of the magnetic catalyst with the NaBH₄ solution using an external magnet. Moreover, the real-time tunability of the output power of the NaBH₄-based fuel cell system without additional balance-of-plants was realized. This strategy may contribute to the improvement of the hydrolysis of borohydrides toward practical H₂ generator applications, and could be extended to other liquid-phase hydrogen production systems.