Highly active and durable catalyst for hydrogen generation by the NaBH₄ hydrolysis reaction : CoWB/NF nanodendrite with an acicular array structure

Abstract

Sodium borohydride (NaBH4) hydrolysis is a promising technology to produce high-purity hydrogen (H2) on-site for fuel cells. However, the widespread applications of this technology are hampered by the low catalytic activity and poor stability of the catalyst for hydrogen production. To develop a low-cost catalyst with high activity and good stability, a novel CoWB catalyst supported by nickel foam was prepared by the pulse electrodeposition method for H2 production from a NaBH4 alkaline solution. The SEM results revealed that in the special microstructure of nanodendrites with acicular arrays, CoWB was uniformly plated on the surface of the Ni foam (NF) substrate and firmly adhered to the surface. The tungsten doping decreased the activation energy to as low as 18.15 kJ mol−1. The CoWB/NF catalyst exhibited higher hydrogen producing performance, and the hydrogen generation rate (HGR) reached 14.13 L min−1·g−1 cat, which was comparable to that of the noble metal catalyst. More importantly, the catalyst demonstrated very good stability, as the catalytic activity was maintained at 82% of its initial activity after 800 h of usage. The CoWB/NF catalyst of the hydrogen generator contributed to the generation of hydrogen with 99.9871% purity at an HGR of 1.07 L/min. This study demonstrated that the novel CoWB/NF catalyst is very promising for hydrogen production from the NaBH4 hydrolysis reaction.