Cation Vacancies Promote Singlet Oxygen–Mediated Piezo‐Catalytic H 2 O 2 Synthesis via Orbital Antibonding Modulation

ABSTRACT Piezo‐catalytic hydrogen peroxide (H 2 O 2 ) synthesis offers a sustainable route for harnessing mechanical energy to drive chemical transformations; however, its efficiency and selectivity are fundamentally constrained by strong metal–oxygen interactions that hinder superoxide desorption and bias oxygen reduction toward undesired pathways. A central but largely unexplored question is how the electronic occupancy of antibonding states at metal–oxygen intermediates govern these reaction outcomes. Here, we show that regulating antibonding orbital occupancy provides a decisive lever to weaken superoxide binding and redirect piezo‐catalytic oxygen reduction toward a singlet oxygen ( 1 O 2 )–mediated two‐electron pathway. This principle is realized in bismuth titanate through the introduction of Ti cation vacancies, which modify the surface electronic structure and polarization behavior. Spectroscopic analyses and density functional theory calculations reveal that a downward shift of the Ti d‐band center increases antibonding orbital filling, facilitating superoxide desorption and subsequent 1 O 2 formation. As a result, H 2 O 2 generation is significantly increased, reaching a production rate of 1516 µmol g − 1 h − 1 under ambient conditions, together with stable performance and demonstrate applicability in antimicrobial and pollutant degradation processes. These results establish antibonding orbital regulation as a mechanistic design principle for steering piezo‐catalytic reaction pathways toward non‐radical H 2 O 2 synthesis.