Precise structural regulation in high entropy quadruple perovskite for enhanced alkaline hydrogen evolution reaction

Despite encouraging advances in ruthenium-based perovskites for alkaline hydrogen evolution reaction (HER), the design of their active sites remains a significant challenge. The entropy-driven strategy has recently emerged to enhance electrocatalytic performance, by precisely modulating the adsorption capacity of intermediates through tunable elements. Here, we discover a superior A-site-ordered high-entropy quadruple perovskite (HEQP) catalyst, (Na 0.2 Ca 0.2 Sr 0.2 Nd 0.2 La 0.2 )Cu 3 Ru 4 O 12, demonstrating an exceptional overpotential of 36 mV at 10 mA/cm2 and a small Tafel slope of 39 mV/dec during alkaline HER process. Moreover, (Na 0.2 Ca 0.2 Sr 0.2 Nd 0.2 La 0.2 )Cu 3 Ru 4 O 12 exhibits remarkable stability over 10,000 cycles of operation and retains negligible activity loss over 48 h. The high-entropy property provides a stable platform for hydrogen generation, preventing crystal collapse and allowing for the optimization of electronic configuration to enhance the uptake and desorption of intermediates.