Cooperative Redox Catalysis of N ₂ O Decomposition by Short‐Range RhO _x and CeO

ABSTRACT

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.