Coupling Geometric Curvature to Electronic Band Curvature: Electron Effective Mass as a Handle for Mechanochemical Reactivity

Mechanochemistry provides a promising strategy for controlling chemical reactivity, but the microscopic origin of reactivity changes under mechanical deformation remains unclear. Here, we show that ripple-induced curvature in two-dimensional materials can directly tune electronic band curvature and electron effective mass, thereby modulating reactivity. Using rippled graphene bearing transition-metal single-atom sites, we find that curvature systematically alters the effective mass, producing more localized and more reactive electronic states within an otherwise extended semimetallic framework. This modulation correlates strongly with adsorption at the metal sites, showing that reactivity can be controlled through curvature-driven changes in fundamental descriptors of the pristine surface electronic structure. Crystal orbital Hamilton population analyses further reveal that bond strength tracks effective mass, establishing a chemically intuitive connection between geometric curvature, carrier localization, and chemical bonding. Together, these results reveal a new mechanism for curvature-enhanced reactivity. More broadly, they motivate renewed examination of mechanochemical reactivity in curved and mechanically perturbed materials.