Turing‐Patterned Noble‐Metal/Si Catalysts via a Top‐Down Route for Enhanced Hydrogen Evolution

Turing‐patterned architectures offer rich interfacial sites and structural complexity advantageous for electrocatalysis. Here we demonstrate a general top‐down strategy to construct noble‐metal–silicon Turing‐patterned nanocatalysts by selectively etching LaNM 2 Si 2 (NM = Ru, Ir, Rh) intermetallics. Extending beyond Ru, sequential acid–alkali etching of LaIr 2 Si 2 yields a highly exposed Ir–Si reaction–diffusion network that serves as an efficient hydrogen evolution reaction catalyst. The optimized LaIr 2 Si 2 ‐derived material delivers low overpotentials (99 mV in alkali; 89 mV in acid at 100 mA cm −2 ), fast kinetics, and exceptional stability at high current density. This work establishes a compositionally versatile route to Turing‐patterned electrocatalysts and highlights the catalytic potential of top‐down–derived Ir–Si interfaces.