Electrocatalytic H2O2 production via the two-electron oxygen reduction reaction (ORR) is a highly sustainable alternative to industrial methods. To further optimize non-noble catalysts, we report an interfacial engineering strategy to stabilize the metastable P63/mmc-La2O3 phase on SrTiO3. This symmetry evolution from the low-symmetry P3-m1 (trigonal) to the high-symmetry P63/mmc (hexagonal) space group yields a composite with >95% H2O2 selectivity. Mechanistic studies demonstrate that the symmetry-regulated interface optimizes *OOH conversion and suppresses O–O bond cleavage. This work offers a robust design principle for high-performance, noble-metal-free H2O2 electrosynthesis.
袁寒松 et al. (Wed,) studied this question.