Metal-free boron nitride has recently been reported to exhibit high catalytic activity and selectivity towards oxidative dehydrogenation of propane (ODHP). Despite several experimental studies, the exact nature and function of the active sites in this emerging catalyst are unknown. In the present work, density functional theory calculations are combined with microkinetic modeling to systematically explore the ODHP on oxygen passivated boron nitride nanoribbons (BNNRs). The relative stabilities of different edge structures of BNNR were examined using ab initio thermodynamic analysis, and the most stable oxygen passivated edge structure was used for a mechanistic study. Microkinetic analysis revealed that a N2O or NOx-type active site is active and selective for the conversion of propane to propene. In addition to a heterogeneous catalytic cycle, the proposed N2O/NOx-type active sites are expected to be able to generate gas phase C3H7˙, which in turn can trigger gas phase reactions of ODHP as experimentally speculated.