Perovskites as precursors of bimetallic Rh–Ni catalysts for ethanol steam reforming: effect of Rh inclusion on catalyst structure and behavior

Abstract

Ni–Rh bimetallic catalysts are successfully obtained from pure LaAl1-x-yRhxNiyO3 perovskites synthetized by the citrate method, and the samples are characterized by X-ray diffraction, temperature programmed reduction, X-ray photoelectron spectroscopy, SEM, and TG techniques. The inclusion of Rh into the perovskite induces structural changes that modify the reducibility behavior and oxygen mobility; in particular, the presence of Rh enhances the reducibility of Ni. All catalysts are active in the ethanol steam reforming reaction, where the highest catalytic activity and stability is obtained for the catalyst Rh0.02Ni0.2, which presents the highest reducibility and a higher content of oxygen vacancies. Based on the best catalyst, a methane reforming reaction is proposed as an additional way to produce H2. Catalysts with lower amount of Ni are prone to carbon deposition affecting performance.