Hydrogen Bonds Induced Sabatier Phenomenon for Amorphous IrO_{<b><i>x</i></b>} in Acidic Oxygen Evolution Reaction.

Abstract

The Sabatier principle, which optimizes electrocatalyst design by balancing intermediate adsorption and desorption, typically manifests as a volcano trend in catalytic activity. Here, we introduce a hydrogen-bond-induced Sabatier phenomenon that enables the design of highly efficient Ir-based electrocatalysts. The optimized amorphous IrO_<i>x</i> catalyst achieves a high mass activity of 1741 A g_Ir^-1, a 27-fold improvement over commercial IrO₂ (64 A g_Ir^-1), alongside a durability (S-number: 1.9 × 10⁶) with no apparent degradation in 870 h, far surpassing the benchmarks of commercial IrO₂ (S-number: 3.4 × 10⁴). Operando X-ray absorption spectrometry, in situ Fourier transform infrared spectroscopy, and online differential electrochemical mass spectrometry measurements reveal the absence of lattice oxygen participation and a self-healing mechanism involving the Ir valence state and Ir-O bond length. Density functional theory calculations highlight reduced energy barriers for *OOH formation and strengthened Ir-O bonds as critical factors driving enhanced performance. Moreover, this H-bond modulation strategy is generalized to other metal oxides in acidic conditions, including RuO_<i>x</i>, RhO_<i>x</i>, and CoO_<i>x</i>, highlighting its versatility and potential to revolutionize electrocatalyst design. These findings establish H-bond modulation as a transformative, noncovalent approach for improving activity and stability in metal oxide electrocatalysts.