La-doped supported Ni catalysts for steam reforming of methane. (19th April 2019)

• Record Type: Journal Article
• Authors: Boudjeloud, M.; Boulahouache, A.; Rabia, C.; Salhi, N.
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 20(2019)
• Page Start: 9906
• Page End: 9913
• Publication Date: 2019-04-19
• Subjects: Nickel -- Lanthanum -- Promoter -- Hydrogen -- Steam reforming; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.01.140
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Ni-La/α-Al2 O3 catalysts at different Ni/La ratio of respectively 7/3, 8/2 and 9/1 to obtain a material with total loading of 10 wt% as used in industrial methane steam reforming field are prepared with incipient wetness impregnation method. Various techniques including TGA-DTA, XRF, XRD, particles size, H2 -RTP and BET are used to characterize materials and their catalytic performance is evaluated during the steam reforming reaction at different temperatures ranging from 500 to 800 °C. Only NiO and α-Al2 O3 phases are evidenced by DRX indicating probably the presence of small lanthanum crystallites in high dispersion state. Addition of La may cause strong change at the surface of NiO sites. Substitute Ni by La leads to smaller and well dispersed NiO particles sizes with strong metal support interaction (SMSI). TPR analysis reveals the reduction of Ni species with high Ni-La-Al interactions particularly well observed with 3 wt%La catalyst. The small Ni particles sizes highly dispersed on the support enhance the dissociative adsorption of CHx species. The highest H2 yield is obtained with 7Ni-3La/Al catalyst reaching 94% at 800 °C. Graphical abstract: Graphical sketch illustrating deposition, calcination and reduction steps of the catalysts.Image 1 Highlights: Substituting Ni by La causes strong change at the NiO surface species. Adding La decreases sensitively average NiO crystallites sizes. NiO particles sizes are in high dispersion state with SMSI. Ni interacting strongly both with La and support improves dissociative adsorption of CHx species.