Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instabi...Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.展开更多
基金supported by the National Natural Science Foundation of China (21978278, 21838003 and 91834301)the Shanghai Scientific and Technological Innovation Project (18JC1410500 and 19JC1410400)the Fundamental Research Funds for the Central Universities (222201718002)。
文摘Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.
