• Ir nanoclusters supported on nitrogen-doped carbon frameworks (Ir@NC) exhibit exceptional HER activity with an overpotential of only 23 mV at 10 mA cm−2 in acidic media.
• The strong electronic interaction between Ir clusters and the N-doped carbon support optimizes the electronic structure of Ir, enhancing catalytic performance.
• The three-dimensional porous structure of the ZIF-8-derived carbon framework exposes abundant active sites, contributing to high efficiency.
• The simple, scalable synthesis method and excellent stability (over 24 h) make Ir@NC a promising candidate for industrial acidic water electrolysis.