Efficient Hydrogen Peroxide Generation Modulated by Crystal-Plane Engineering in Ti₂O₃

The development of stable and selective electrocatalysts for hydrogen peroxide (H₂O₂) synthesis via the two-electron oxygen reduction reaction (2e^- ORR) is critical for sustainable green chemistry. However, the performance of transition metal oxides (TMOs) is often severely limited by the thermodynamic tendency to expose crystal planes with sluggish kinetics. Herein, we present a doping-mediated crystal-plane-engineering strategy to overcome these constraints, using Ti₂O₃ as a model system. Guided by a d-orbital morphology descriptor, we identified specific crystal planes, including (012) and (113)/(104), as theoretically active sites. Experimentally, Ni doping acted as an effective crystal-plane-directing agent, successfully modulating surface energies to induce the synergistic exposure of these target planes. Consequently, the optimized Ni-Ti₂O₃ electrocatalyst delivered an H₂O₂ selectivity (94.4%) and yield of 2.56 mol g_cat ^-1 h^-1 at 0.4 V vs. RHE. This work demonstrates the efficacy of orbital-driven plane control, providing a generic paradigm for the rational design of high-performance TMO electrocatalysts for advanced energy applications.