Cooperative Redox Catalysis of N₂O Decomposition by Short‐Range RhOₓ and CeOₓ Anchored to Co₃O₄

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 N₂O decomposition containing short-range ordered RhOₓ and CeOₓ species anchored to the Co₃O₄ spinel. The activity enhancement relative to Co₃O₄ is non-additive with respect to the RhOx/Co₃O₄ and CeOx/Co₃O₄ 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 N₂O decomposition. Kinetic analysis and operando modulated excitation x-ray absorption spectroscopy (ME-XAS) provide direct mechanistic evidence that N₂O decomposition proceeds via a multi-site, cooperative Mars-van Krevelen pathway, in which Co₃O₄–CeO₂ acts as an oxygen reservoir enabling the redox cycling of RhOₓ 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.