Large-Scale Nanofiber Manufacturing| Engineering Ru and Ni sites relay catalysis and strong metal-supportinteraction for synergetic enhanced electrocatalytic hydrogenevolution performance

 Prof. Xu Guancheng & Prof. Zhang Li at Xinjiang University: Electrospinning Fabrication of Ru-doped Ni Nanoparticles Embedded in Carbon Nanofibers for Efficient Hydrogen Evolution Reaction

Hydrogen energy, as a clean energy source, holds significant importance for achieving carbon neutrality and promoting low-carbon transitions. Electrocatalytic water splitting is considered the most promising low-carbon and environmentally friendly hydrogen production technology. This technology relies on electricity to drive the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. The efficiency of HER directly affects the overall energy conversion efficiency of water electrolysis. Therefore, the rational design of alkaline HER electrocatalysts with excellent catalytic activity and stability is crucial for improving overall water-splitting efficiency, facilitating the industrial-scale application of large-scale green hydrogen production.

Recently, a team led by Prof. Xu Guancheng and Prof. Zhang Li at Xinjiang University successfully prepared Ru-doped Ni nanoparticles embedded in carbon nanofiber catalysts (Ru1Ni6/CNF) via electrospinning followed by heat treatment. The strong metal-support interaction (SMSI) formed between the Ru-doped Ni nanoparticles and the graphitic carbon shell not only protects the catalyst from thermal agglomeration-induced surface area loss but also promotes charge transfer. The graphitic carbon shell effectively shields the catalyst, slowing its (electro)chemical corrosion. The resulting Ru1Ni6/CNF catalyst exhibits outstanding alkaline HER activity and stability.The findings were published in Chemical Engineering Journal under the title "Engineering Ru and Ni sites relay catalysis and strong metal-support interaction for synergetic enhanced electrocatalytic hydrogen evolution performance."

Figure 1. Preparation process and microstructure characterization of Ru1Ni6/CNF catalyst.

Figure 2. Bond valence and coordination structure of Ru1Ni6/CNF catalyst.

The Ru-doped Ni nanoparticles embedded in carbon nanofibers (Ru1Ni6/CNF) were prepared via electrospinning and subsequent heat treatment. Scanning electron microscopy (SEM) images show that the pyrolyzed Ru1Ni6/CNF retains the one-dimensional nanofiber structure of the precursor, with a diameter of approximately 300 nm. The surface of Ru1Ni6/CNF exhibits a rough and porous structure, exposing more active sites and facilitating electrolyte penetration. XPS confirms electron interaction between the graphitic carbon layer and Ru-doped Ni nanoparticles, while synchrotron radiation further reveals the presence of Ni–Ni and Ni–Ru bonds.

Figure 3. Alkaline hydrogen evolution performance of Ru1Ni6/CNF catalyst.

Figure 4. Acidic hydrogen evolution performance of Ru1Ni6/CNF catalyst and alkaline hydrogen evolution performance of RuCo/CNF, RuFe/CNF and RuCu/CNF.

Figure 5. HER mechanism analysis of Ru1Ni6/CNF catalyst.

In alkaline solution, Ru1Ni6/CNF demonstrates a low overpotential of 14 mV at a current density of 10 mA cm⁻² and excellent stability over 400 hours. In acidic solution, the catalyst also exhibits superior HER activity, requiring only 54 mV overpotential at 10 mA cm⁻². Additionally, in alkaline electrolyte, RuCo/CNF, RuFe/CNF, and RuCu/CNF all outperform Co/CNF, Fe/CNF, and Cu/CNF, indicating the universal enhancement of HER performance through Ru doping.DFT calculations reveal that Ru sites promote water adsorption and dissociation. Ru doping weakens H* adsorption on Ni sites, facilitating H* desorption. The synergy between Ru and Ni sites further enhances reaction kinetics. This dual-active-site catalyst overcomes the limitation of single-active-site catalysts, which only exhibit high catalytic activity in a single HER step, achieving overall improvement in HER catalytic performance.This work presents a design strategy for multi-site, multi-functional synergistic catalysts, providing insights for the rational development of environmentally friendly and highly efficient HER catalysts.