Reversed Charge Transfer Enables Dual Active Sites on Ir/hBN for Synergistic N2O Valorization and Propane Selective Oxidation

Valorization of nitrous oxide (N2O) as a mild oxygen source for light alkanes presents a promising and economical method for mitigating global warming. However, activating N2O and alkane together often leads to overoxidation and poor selectivity of the products. To disentangle the trade-off between activity and selectivity, herein, an Ir-based hexagonal boron nitride (hBN) catalyst was synthesized to obtain a reversed charge transfer (RCT) from the support to metal centers, forming dual active sites on Ir clusters and the separation of redox centers, as determined via operando near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and density functional theory (DFT) calculations. Ir/hBN demonstrated a high N2O conversion (99.5%) and syngas yield (95.9 mol of CO kgcat–1 h–1 and 41.9 mol of H2 kgcat–1 h–1) during the selective oxidation of propane (C3H8) at 450 °C. The electron-rich Ir interfacial perimeter sites (Irδ−) enhance N2O adsorption and N–O bond dissociation to produce active O*; however, facial metallic Ir0 sites effectively facilitate C3H8 activation, including dehydrogenation and cracking. The separation of H* and O* intermediates, along with the frustrated H*/O* spillover, effectively facilitates the formation of H2. The *CH2 intermediate from C3H8 breakage migrates and reacts with O* bound to Ir interfacial sites, where it is oxidized to CO32– and subsequently liberates CO. This study provides mechanistic insights into the O element valorization from N2O with synergetic enhancement in selective oxidation of light alkanes.