Hydrolysis of sodium borohydride using a highly stable catalyst of ruthenium nanoparticles supported by cobalt–nickel hydroxide-coated nickel foam

Abstract

Hydrogen is among the most promising episodic energy carriers. Consequently, sodium borohydride has attracted attention owing to its high H content and good stability. However, its applications are limited by slow reaction kinetics, and it is necessary to identify new high-performance catalysts with good durability. Nickel foam (NF) is a stable, hollow, and porous carrier material that is inexpensive and widely available. In this study, an NF framework was coated with Co–Ni layered double hydroxide (LDH) using a one-step hydrothermal method. Thereafter, a Ru@CoNi-LDH/NF composite catalyst was prepared by etching Ru on the CoNi-LDH surface via an impregnation method and reducing it in situ with a NaBH4 solution. Inductively coupled plasma mass spectrometry was used to analyze the Ru content of the sample, which was found to be 1.27 wt%. X-ray photoelectron spectroscopy was employed to confirm the existence of elemental Ru. Catalysts prepared using precursors with different ratios of Co and Ni were investigated. The catalytic performance of the catalyst prepared with a Co to Ni ratio of 1:2 was 38 L·min−1·gRu−1 at 30 °C, demonstrating the beneficial effect of the NF on performance. The catalyst maintained 79.3 % of its initial activity after ten cycles, owing to the framework and high-activity catalyst loading.