Role of the nanoparticles of Cu-Co alloy derived from perovskite in dry reforming of methane

Highlights: • LaCoO₃ and LaCu_0.55Co_0.45O₃ were synthesis from perovskite using the sol-gel method. • Reduction of LaCu_0.55Co_0.45O₃ afforded nanoparticle Co⁰ with high surface area. • Copper addition to LaCoO₃ showed improved resistance to coke deposition. • Deactivation of the LaCoO₃ catalyst is correlated with the formation of CoO. -- Abstract: Enhanced the carbon resistance and sintering of the metal-active site of catalysts for the dry reforming of methane (DRM) can be achieved by the metal-perovskite interaction. Perovskite-based catalysts LaCoO₃ and LaCu_0.55Co_0.45O₃ were prepared using the sol-gel citrate method. The products obtained, after heat treatment under air at 800 °C, were characterized by several techniques such as: inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauere Emmette Teller method (BET), scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM) and temperature-programmed reduction (TPR). After reduction, the catalysts were evaluated in the reforming of methane reaction under continuous flow with CH₄/CO₂ ratio equal to 1, at atmospheric pressure and temperature ranging from 400 to 700 °C. LaCu_0.55Co_0.45O₃ catalyst exhibit higher activity compared to LaCoO₃. According to the catalytic and characterization results before and after reaction, the higher activity obtained in the case of LaCu_0.55Co_0.45O₃ can be explained by the lower Co particle size and formation of Cu-Co alloy during the reduction which prevents the CoO formation.