A novel design of solid-state NaBH₄ composite as a hydrogen source for 2 W PEMFC applications

Hydrolysis of sodium borohydride (NaBH₄) is a promising method for on-board hydrogen supply to polymer electrolyte membrane fuel cells (PEMFC). This article presents an attempt to design a novel solid-state NaBH₄ composite, which is made up of NaBH₄ powder, Co²⁺/IR-120 catalyst and silicone rubber, for hydrogen generator. The silicone rubber can act as a stabilizer in the solid-state NaBH₄ composite because of its surface hydrophobicity leading to reduced diffusion rate of water into the composite. The solid-state NaBH₄ composite can produce hydrogen stably near 25 mL min^-1 for at least 2 h without employment of any mechanical control system. Using the hydrogen generated from the solid-state NaBH₄ composite, a 2 W PEMFC stack is successfully operated to power a cellular phone.