Complex Alloy and Heterostructure Nanoparticles Derived from Perovskite Oxide Precursors for Catalytic Dry Methane Reforming

Abstract

We have developed a general route for combining Ni, Fe, Co, Cu, and Pd in a nanoparticle using the exsolution mechanism from LaFe0.7Ni0.1Co0.1Cu0.05Pd0.05O3 perovskite oxide precursors. The strong adherence of the nanoparticles to the support yields attractive catalytic properties for dry methane reforming, such as coke resistance and thermal sintering suppression. The reduction of the precursors at 700 and 900 °C yielded NiCoCuPd or NiFeCoCuPd nanoparticles with a size-dependent phase transition from a complex concentrated alloy to phase-separated heterostructures. Our findings indicate that smaller concentrated alloy nanoparticles (∼10 nm) are more effective for methane activation than larger (>20 nm) phase-separated nanoparticles.