Hydrogen Bonds Induced Sabatier Phenomenon for Amorphous IrO<sub><b><i>x</i></b></sub> in Acidic Oxygen Evolution Reaction
Hongzhe Xu, Haijiao Lu, Guoqiang Shen, Zhiliang Wang, Yanzhao Zhang, Kai Wang, Peng Chen, Dongxu He, Shuang Kong, Ailong Li, Guangyu Zhao, Yonggang Jin, Qin Li, Lianzhou Wang
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 x catalyst achieves a high mass activity of 1741 A g Ir –1, a 27-fold improvement over commercial IrO 2 (64 A g Ir –1 ), alongside a durability (S-number: 1.9 × 10 6 ) with no apparent degradation in 870 h, far surpassing the benchmarks of commercial IrO 2 (S-number: 3.4 × 10 4 ). 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 x, RhO x, and CoO x, 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.