Ni/La2O3 catalysts for dry reforming of methane: Effect of La2O3 synthesis conditions on the structural properties and catalytic performances

10 wt%Ni/La2O3 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 La3Ni2O6). The gradient temperature DRM tests (400-800 degrees C) reveal higher catalytic activity of Ni-La CA (at 650 degrees C, X(CO2) = 65.7%, X(CH4) = 54.6%, H-2/CO = 0.71). The Ni-La CA-NH3 shows higher stability (at 650 degrees C and 24 h, X(CO2): 73.7% => 76.4%, X(CH4): 64.7% => 64.6%, H-2/CO: 0.77 => 0.72). For both catalysts, La2O2CO3 phase is formed after long run tests at 650 degrees C 24 h, with the greater TGA weight loss and stronger deactivation being observed for Ni-La CA. The H-2-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. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

10 wt% Ni/La2O3 catalysts for dry reforming of methane were synthesized by wetness impregnation of lanthana supports prepared using sol-gel citric method with and without NH3 addition. The Ni-La CA catalyst showed higher catalytic activity at 650 degrees Celsius, while Ni-La CA-NH3 exhibited higher stability under the same temperature and time conditions. After long run tests, both catalysts formed La2O2CO3 phase, but Ni-La CA showed more severe deactivation.