Regulation A-site of ruthenium pyrochlores to enhance acidic oxygen evolution activity and stability

Exploring the relationship between A-site atoms and the ruthenium pyrochlore oxides (A(2)Ru(2)O(7)) structure is crucial for designing efficient electrocatalysts for acidic water oxidation. Here, we manipulate A-site atoms by introducing lanthanide elements (Nd, Sm, Eu, and Ho) in a rational manner. It was shown that different A-site atoms have little effect on the electronic valence of the Ru and O ions, but they do impact the structure of A(2)Ru(2)O(7). The catalyst activity and stability increased gradually as the A-site ion radius decreased. Ho2Ru2O7 with the lowest Ru content displayed the lowest overpotential (280 mV) at 10 mA/cm(2), showing the longest stability (>20,000 s) compared to the other samples. This study suggests that regulating non-active sites can enhance the performance of acidic water splitting.

Automated summary

Exploring the relationship between A-site atoms and the structure of ruthenium pyrochlore oxides (A(2)Ru(2)O(7)) is crucial for designing efficient electrocatalysts for acidic water oxidation. This study manipulated A-site atoms by introducing lanthanide elements and found that they have little effect on the electronic valence of the Ru and O ions, but do impact the structure of A(2)Ru(2)O(7). The catalyst activity and stability increased gradually as the A-site ion radius decreased, with Ho2Ru2O7 demonstrating the highest stability and lowest overpotential.