Catalysts for ethanol dry reforming based on high-entropy perovskites

Abstract

Ethanol dry reforming is a promising way to produce syngas and hydrogen due to utilization of carbon dioxide and ability to produce ethanol using renewable sources. Main problem associated with ethanol dry reforming reaction is coke formation. Coking suppression can be achieved in a few ways including use of catalysts possessing required oxygen transport properties. High entropy oxides are of interest in application as catalysts for ethanol dry reforming and other reactions due to their structural stability, disordering features and tunability of functional properties. In this work, the catalysts based on Ni and multiple doped La manganites are studied. The oxides are synthesized by modified Pechini and citrate techniques, and the catalysts are prepared by wetness impregnation. The samples are characterized by XRD, TEM with EDX analysis, XPS. Oxygen transport and redox properties are studied by temperature-programmed isotope exchange of oxygen and reduction. According to structural and morphological studies, the samples are nanosized and form perovskite-like structure. The surface features of samples were characterized by XPS. The samples demonstrate a moderate oxygen mobility (D* up to ∼10^–12 cm²/s at 700 °C) required for catalytic operation and coking suppression. Tests in ethanol dry reforming demonstrated fine performance and good stability in the reaction conditions.