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

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.