Boosting HER Activity of FeCoNiMnZn High-Entropy Alloys supported on Nitrogen-doped Carbon Nanotubes

The hydrogen evolution reaction (HER) is critical for sustainable hydrogen production via water splitting. High-entropy alloys (HEAs) have emerged as promising catalysts due to their tunable electronic properties and compositional diversity. While numerous methods exist for synthesizing HEAs, systematic comparisons of these approaches are lacking, and the mechanistic role of support surface engineering in regulating catalytic performance remains underexplored. In this study, three synthesis methods—fast-moving bed heating (FH), carbothermal shock (CTS), and slow heating (SH)—were compared to fabricate HEA nanoparticles on CNTs. The FH method, leveraging its dynamic temperature gradient and ultrafast heating rate, achieved rapid synthesis of highly dispersed HEA nanoparticles with suppressed aggregation. Based on FH method, nitrogen doping via NH 3 calcination further tailored the electronic structure and active-site distribution of CNTs, significantly enhancing HER activity. The optimized FeCoNiMnZn/N-CNTs prepared by FH achieved an overpotential of 184   mV at 10   mA/cm². Density functional theory (DFT) calculations revealed that nitrogen incorporation induces near-ideal hydrogen adsorption free energy (ΔG H⁎ ), accelerating H adsorption/desorption kinetics. This work not only advances the rational selection of synthesis protocols for HEA catalysts but also underscores the transformative potential of support surface engineering in optimizing catalytic behavior for clean energy technologies.