Syngas production by CO 2 reforming of methane on LaNi x Al 1 - x O 3 perovskite catalysts: influence of method of preparation

• Published in: Journal of chemical sciences (Bangalore, India) Vol. 129; no. 11; pp. 1787 - 1794
• Main Authors: Sagar, T V, Padmakar, D, Lingaiah, N, Rama rao, K S, Reddy, I A K, Sai Prasad, P S
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.01.2017
• Subjects: Aluminum; Bimetals; Carbon dioxide; Catalysis; Catalysts; Crystal defects; Fourier transforms; Infrared spectroscopy; Metal particles; Methane; Nickel; Reforming; Sintering; Sol-gel processes; Strong interactions (field theory); Synthetic fuels; X-ray diffraction
• ISSN: 0974-3626; 0973-7103
• DOI: 10.1007/s12039-017-1359-2

Two series of LaNixAl1-xO3 catalysts (0≤x≤1) were prepared by hydrothermal and sol–gel methods and characterized by X-ray diffraction (XRD), BET surface area, Temperature programmed reduction (TPR) and Fourier- transform infrared spectroscopy (FT-IR) techniques. The performance of these catalysts was studied for CO2 reforming of methane (also called dry reforming of methane, DRM) at atmospheric pressure and in the temperature range of 600-800∘C, maintaining a space velocity of 28,800h-1. Catalysts containing trimetallic perovskite showed higher CH4 and CO2 conversions than the bimetallic perovskite, due to the strong interaction of Ni with the former. Strong interaction increased the reduction temperature of the active species and reduced the sintering of metallic particles. At 800∘C, the sol–gel catalysts reached their maximum activity in terms of both CH4 and CO2 conversions at x = 0.3, whereas the same for hydrothermal catalysts required a Ni ratio x = 0.6. The trimetallic perovskite formation was responsible for the catalyst stability. A comparison of the best catalysts from the two series revealed that the hydrothermal catalysts exhibited a slightly better performance during the time on stream analysis. The results are interpreted in terms of changes in the physicochemical properties of the catalysts.Graphical Abstract:La–Ni–Al trimetallic perovskite formation gives higher CH4 and CO2 conversions than the La–Ni bimetallic perovskite in the catalysts. The strong interaction between the metallic Ni and the defined structure prevents sintering of metal particles. The high dispersion of Ni enhances the activity. The incorporation of third metal into the bimetallic perovskite lattice increases the lattice defects thereby producing the mobile oxygen, which helps decrease coke accumulation on the surface of the catalysts.