Zirconium-Palladium Interactions during Dry Reforming of Methane

Abstract

Catalytic investigations on chemical-vapor-deposition (CVD)-prepared Pd/Zr0/ZrOxHy inverse model catalysts and Pd/Zr intermetallic compound system in dry reforming of methane (DRM) are presented. DRM, which produces syngas, is an economically favourable way to operate an SOFC by reusing the already heated CO2 exhaust. The catalytic investigations of the Pd/Zr system yield important information for the design of novel electrode materials or external reforming catalysts. From a catalytic perspective, the initially bimetallic Pd-Zr pre-catalyst shows a distinct activity for dry reforming of methane. This activity can be ascribed to synergistic bifunctional cooperation of palladium and zirconium. Moreover, the investigations clearly demonstrate that metallic Zr is crucial to observe any activity. Therefore, different bulk and surface sensitive methods are used to follow the evolution of structural and redox changes of Zr. Studies of single-crystalline Pd(111) show that Zr0 is located exclusively in subsurface layers after annealing in vacuum and prior to reaction.