Cooperative Redox Catalysis of N ₂ O Decomposition by Short‐Range RhO <i> _x </i> and CeO <i> _x </i> Anchored to Co ₃ O ₄

Hybrid materials based upon mixed metal oxides provide an effective strategy to boost catalytic performance through redox‐induced interfacial engineering. Herein, we present an efficient catalyst toward N 2 O decomposition containing short‐range ordered RhO x and CeO x species anchored to the Co 3 O 4 spinel. The activity enhancement relative to Co 3 O 4 is non‐additive with respect to the RhO x /Co 3 O 4 and CeO x /Co 3 O 4 interfaces and is uniquely linked to the modulation of the Co and Rh oxidation states at a synergistic Rh–O–Co–O–Ce interface. This ensemble provides increased redox flexibility and facilitated lattice oxygen activation, resulting in markedly enhanced N 2 O decomposition. Kinetic analysis and operando modulated excitation x‐ray absorption spectroscopy (ME‐XAS) provide direct mechanistic evidence that N 2 O decomposition proceeds via a multi‐site, cooperative Mars‐van Krevelen pathway, in which Co 3 O 4 –CeO 2 acts as an oxygen reservoir enabling the redox cycling of RhO x species. This study highlights the ability of mixed metal oxide catalysts to exploit interfacial effects to achieve improved activity in redox‐mediated reactions and offers a rationale for the engineering of metal oxide–metal oxide catalysts guided by operando spectroscopy.