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

10 wt%Ni/LaO catalysts for dry reforming of methane (DRM) were synthesized by wetness impregnation of lanthana supports prepared using sol-gel citric method with and without NH addition (Ni-La CA-NH and Ni-La CA, respectively). The support preparation conditions affect the nature, phase composition, and distribution of Ni phases (LaNiO, NiO and LaNiO). The gradient temperature DRM tests (400-800 °C) reveal higher catalytic activity of Ni-La CA (at 650 °C, X(CO) = 65.7%, X(CH) = 54.6%, H/CO = 0.71). The Ni-La CA-NH shows higher stability (at 650 °C and 24 h, X(CO): 73.7% => 76.4%, X(CH): 64.7% => 64.6%, H/CO: 0.77 => 0.72). For both catalysts, LaOCO 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 H-reduced Ni La CA-NH features ultrasmall (1-2 nm) Ni NPs strongly interacting with the support. Catalyst nature affects the amount of carbon coke formed.