Ni/La2O3 catalysts for dry reforming of methane: Effect of La2O3 synthesis conditions on the structural properties and catalytic performances. (11th February 2021)

• Record Type: Journal Article
• Authors: Grabchenko, M.; Pantaleo, G.; Puleo, F.; Vodyankina, O.; Liotta, L.F.
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 11(2021)
• Page Start: 7939
• Page End: 7953
• Publication Date: 2021-02-11
• Subjects: La2O3 synthesis -- Sol-gel citric method -- NH3 effect -- LaNiO3 -- NiO -- La3Ni2O6 phases; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.12.026
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: 10 wt%Ni/La2 O3 catalysts for dry reforming of methane (DRM) were synthesized by wetness impregnation of lanthana supports prepared using sol-gel citric method with and without NH3 addition (Ni–La CA-NH3 and Ni–La CA, respectively). The support preparation conditions affect the nature, phase composition, and distribution of Ni phases (LaNiO3, NiO and La3 Ni2 O6 ). The gradient temperature DRM tests (400–800 °C) reveal higher catalytic activity of Ni–La CA (at 650 °C, X(CO2 ) = 65.7%, X(CH4 ) = 54.6%, H2 /CO = 0.71). The Ni–La CA-NH3 shows higher stability (at 650 °C and 24 h, X(CO2 ): 73.7% => 76.4%, X(CH4 ): 64.7% => 64.6%, H2 /CO: 0.77 => 0.72). For both catalysts, La2 O2 CO3 phase is formed after long run tests at 650 °C 24 h, with the greater TGA weight loss and stronger deactivation being observed for Ni–La CA. The H2 -reduced Ni La CA-NH3 features ultrasmall (1–2 nm) Ni NPs strongly interacting with the support. Catalyst nature affects the amount of carbon coke formed. Graphical abstract: Image 1 Highlights: Two La2 O3 oxides were prepared with citric acid method with and without NH3 . La(OH)3 was encapsulated into the core of large La2 O3 aggregates at pH ~2. Ni(NO3 )2 solution partially diffused inside the support (pH~2) to form NiO. La3 Ni2 O6 was the main Ni precursor formed on the support prepared with NH3 . Small Ni NPs tightly connected with La2 O3 were observed after La3 Ni2 O6 reduction.