Ruthenate perovskite with face-sharing motifs for sustainable alkaline hydrogen evolution

Abstract Hydrogen-centered electrochemical technologies play a vital role in sustainable energy conversion and storage. One of the challenges in achieving cheap hydrogen is to bridge the gap between advanced electrocatalysts and highly effective electrodes. Here, we synthesized BaRuO 3 in four polymorphs with distinct RuO 6 connections to rationalize the impact of crystal structure feature on transferable alkaline hydrogen evolution activity. The 9 R -BaRuO 3 displays the best hydrogen evolution reaction activity and stability in alkaline solution with a small Tafel slope of 30 mV dec -1 and a low overpotential of η 10 < 51 mV, which is comparable to Pt/C and superior to the most highly efficient ruthenium-based oxide hydrogen evolution catalysts reported to date. Such performance is ascribed to its high intrinsic activity that is delivered by the d-d interaction and optimal intermediate adsorption. More importantly, 9 R -BaRuO 3 can be easily synthesized on a large scale as demonstrated by the 9 R -BaRuO 3 -500 g sample in this study. The high intrinsic activity and micron size of 9 R -BaRuO 3 powders enable a successful performance transfer from a lab-based three-electrode system to a commercial alkaline electrolyser operated under industrial conditions. The findings presented here not only demonstrate a robust and efficient HER electrocatalyst for practical electrolysers, but also emphasize the effect of structural features in the design of advanced electrocatalysts.