Hierarchical Porous NiCo/HZIF-8 Catalyst for Highly Efficient Hydrogen Generation from Sodium Borohydride Hydrolysis

Abstract

Designing an efficient catalyst for NaBH4 hydrolysis remains challenging. In this work, the Ni-Co nanocatalyst supported by the zeolitic imidazolate framework (NiCo/HZIF-8) was successfully prepared by an impregnation–chemical reduction method. The microstructure, catalytic activity, and durability of the nanocatalyst were investigated. The as-prepared NiCo/HZIF-8 nanocatalyst shows a hierarchical porous structure with high specific surface area and good dispersion for the metal nanoparticles (MNPs), which is beneficial to exposing active sites and promoting catalytic performance. The activation energy (Ea) for the hydrolysis of NaBH4 catalyzed by NiCo/HZIF-8 is as low as 32.01 kJ·mol–1, and the maximum turnover frequency (TOF) is 41,254 mLH2 · gM–1 · min–1, surpassing the performance of numerous non-noble metals and even some noble metal nanocatalysts. In addition, the NiCo/HZIF-8 nanocatalyst can retain 85.5% of its initial catalytic activity for NaBH4 hydrolysis after five cycles.