Hierarchically structured rugae-like RuP3–CoP arrays as robust catalysts synergistically promoting hydrogen generation

Abstract

Designing a highly active and stable catalyst for NaBH₄ hydrolysis is a key step towards overcoming the challenges of hydrogen storage. Herein, we have developed a controllable strategy to fabricate a series of hierarchically structured cobalt-ruthenium-phosphide arrays on nickel foam (Co–Ru–P@NF) as a highly efficient and stable catalyst for hydrogen generation from NaBH₄ hydrolysis in alkaline media. SEM and TEM analyses show that the interconnected rugae-like Co–Ru–P arrays are vertically grown on the surface of Ni foam, together with uniformly distributed RuP₃ nanoclusters on the surface of CoP nanosheets. More importantly, the optimized Co–Ru–P@NF catalyst exhibits an outstanding catalytic performance on NaBH₄ hydrolysis in alkaline media with a high turnover frequency (TOF) of 2123.6 mol_H2 min⁻¹ mol_Ru⁻¹ at 25 °C, which is one of the highest known so far. Furthermore, the exceptional catalytic performance is in line with the outcome of low activation energy (40.3 kJ mol⁻¹). Additionally, the catalyst also shows a high stability with less than 8.0% lost after 5 consecutive cycles. The superior catalytic performance is ascribed to the synergetic effect between RuP₃ and CoP species resulting in a significant electron transfer effect, together with the unique morphologies associated with a large specific surface area and open-channels for effective solute transport/adsorption and H₂ gas emissions.