Highly Active Ceria-Supported Ru Catalyst for the Dry Reforming of Methane: In Situ Identification of Ruδ+–Ce3+ Interactions for Enhanced Conversion

Abstract

The metal–oxide interaction changes the surface electronic states of catalysts deployed for chemical conversion, yet details of its influence on the catalytic performance under reaction conditions remain obscure. In this work, we report the high activity/stability of a ceria-supported Ru–nanocluster (<1 nm) catalyst during the dry reforming of methane. To elucidate the structure–reactivity relationship underlying the remarkable catalytic performance, the active structure and chemical speciation of the catalyst was characterized using in situ X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS), while the surface chemistry and active intermediates were monitored by in situ ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Methane activates on the catalyst surface at temperatures as low as 150 °C. Under reaction conditions, the existence of metal–support interactions tunes the electronic properties of the Ru nan...