d-Band Center Tuning of Isolated Bimetallic Sites for Synergistic Catalytic Abatement of N 2 O and NO

Ammonia combustion unavoidably produces nitrogen oxides (NO x ) and nitrous oxide (N 2 O), which impose severe environmental and climatic concerns. Here we demonstrate that tuning the d-band center of isolated Fe and Co bimetallic sites confined within the channels of BEA zeolite enables the synergistic catalytic abatement of N 2 O and NO via the N 2 O–NO–SCR pathway. Electronic coupling between the isolated sites, mediated through the zeolite framework, redistributes charge and shifts the Fe d-band center by ∼0.25 eV toward the Fermi level. This d-band tuning enhances the redox flexibility of Fe while introducing a parallel Co-assisted NO oxidation channel, establishing a dual-site, dual-pathway mechanism, thereby creating favorable synergistic conditions for N 2 O activation and NO oxidation. As a result, FeCo-BEA achieves nearly complete elimination of both pollutants with remarkable selectivity and long-term stability, with the T 90 of N 2 O lowered by 20 °C and the NO conversion consistently maintained at 100%. This study establishes d-band center regulation of isolated single sites as a powerful design principle for multifunctional zeolite catalysts, offering new opportunities for clean and sustainable NH 3 -based energy systems.