4d-2p-4f Gradient Orbital Coupling Enables Tandem Catalysis for Simultaneous Abatement of N 2 O and CO on Atomically Dispersed Rh/CeO 2 Catalyst.

N 2 O and CO coexist in various industrial and mobile sources. The synergistic reaction of N 2 O and CO to generate N 2 and CO 2 has garnered significant research interest, but it remains extremely challenging. Herein, we constructed an atomically dispersed Rh-supported CeO 2 catalyst with asymmetric Rh-O-Ce sites through gradient Rh 4d-O 2p-Ce 4f orbital coupling. This design effectively regulates the 4f electron states of Ce and promotes the electron filling of the O 3π* antibonding orbital to facilitate N-O bond cleavage. Near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) reveals that CO reacts with the surface-adsorbed O* generated by N 2 O decomposition through self-tandem catalysis, accelerating the rate-limiting step in N 2 O decomposition and activating the synergistic reaction of N 2 O and CO at temperatures as low as 115 °C. This work can guide the development of high-performance catalysts using the strategy of high-order orbital hybridization combined with the tandem concept to achieve versatile catalytic applications.