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[Display omitted] • The coke resistance of Ni-based catalysts is improved profoundly by adding Er. • 99.3 % deoxygenation ratio and 64.7 % yield of biofuels is achieved on Ni-Er/50S-Al. • Er promotes the evenly distribution of Ni with smaller particle size. • More surface oxygen vacancies are critical for deoxygenating JO when REEs added. • The strong acidity leads to more coke form with Y added. Herein, three kinds of rare earth elements (Ce, Er and Y) were added to Ni-based catalysts to regulate the deoxygenation ability and coke resistance towards jatropha oil (JO) conversion. Among them, the catalysts with lanthanide metals (Ce and Er) added exhibit positive effects. Conversely, the addition of Y is counterproductive. The one with Er added displays the best catalytic performance, achieving the highest deoxygenation ratio (99.3 %) and product yield (64.7 %), and the resultant biofuel has the highest calorific value (46.02 MJ/kg). The stability of the Ni-Er/50S-Al catalyst is significantly improved due to the enhanced coke resistance compared with the one without Er added. Smaller Ni particle sizes with better dispersion, higher amount of surface Ni0 and surface oxygen vacancies are accomplished by adding Er, which contributes to the enhanced catalytic performance. The addition of Y weakens coke resistance, caused by strong acidity and big Ni particles. This study provides an effective idea for rationally designing catalysts with improved coke resistance and converting vegetable oils into biofuels. [ABSTRACT FROM AUTHOR]

[Display omitted] • The coke resistance of Ni-based catalysts is improved profoundly by adding Er. • 99.3 % deoxygenation ratio and 64.7 % yield of biofuels is achieved on Ni-Er/50S-Al. • Er promotes the evenly distribution of Ni with smaller particle size. • More surface oxygen vacancies are critical for deoxygenating JO when REEs added. • The strong acidity leads to more coke form with Y added. Herein, three kinds of rare earth elements (Ce, Er and Y) were added to Ni-based catalysts to regulate the deoxygenation ability and coke resistance towards jatropha oil (JO) conversion. Among them, the catalysts with lanthanide metals (Ce and Er) added exhibit positive effects. Conversely, the addition of Y is counterproductive. The one with Er added displays the best catalytic performance, achieving the highest deoxygenation ratio (99.3 %) and product yield (64.7 %), and the resultant biofuel has the highest calorific value (46.02 MJ/kg). The stability of the Ni-Er/50S-Al catalyst is significantly improved due to the enhanced coke resistance compared with the one without Er added. Smaller Ni particle sizes with better dispersion, higher amount of surface Ni0 and surface oxygen vacancies are accomplished by adding Er, which contributes to the enhanced catalytic performance. The addition of Y weakens coke resistance, caused by strong acidity and big Ni particles. This study provides an effective idea for rationally designing catalysts with improved coke resistance and converting vegetable oils into biofuels. [ABSTRACT FROM AUTHOR]

xNi/HTASAO5 catalysts (x = 2.5, 3.3, 4.4, 5.8, 8.2) were prepared for CO 2 reforming of methane. No crystalline nickel species formed on the catalysts with lower nickel content (≤4.4%), and large Ni0 crystallite formed on 5.8% (10 nm) and 8.2 wt%Ni/HTASAO5 (17 nm), whereas the surface concentration of Ce3+ decreased with Ni loading. The initial conversion of CH 4 increased from 29.5% to 46.9% with Ni loading. The xNi/HTASAO5 (x ≤ 4.4%) performed stably in the reaction due to the presence of dispersed Ni species and high surface Ce3+ content without coke formation, however, 5.8% and 8.2 wt%Ni/HTASAO5 exhibited decreased activity with time on stream, because of the formation of large Ni particles with lower surface Ce3+, leading to carbon accumulation. Thus, CH 4 conversion stabilized at about 43% and no carbon formed on 4.4 wt%Ni/HTASAO5 with optimum Ni loading. 4.4 wt%Ni/HTASAO5 exhibited high activity and stability in DRM reaction with no coke formation. [Display omitted] • CH 4 conversion stabilized at 43% on 4.4 wt%Ni/HTASAO5 in DRM reaction at 600 °C. • No carbon deposited on the spent catalysts with no crystallite of Ni0. • Ce3+ concentration and adsorbed oxygen increases with decreasing Ni loading. • Reverse water gas shift reaction and carbon removal promoted by surface Ce3+. • The content of medium - strength basic sites increases with decreasing Ni loading. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ni-Mo 2 N catalyst can be effectively convert jatropha oil into high-quality biofuel. • The HDO performance of Ni-Mo 2 N is significantly improved than that of Mo 2 N. • The synergy of Ni and Mo 2 N assists in high biofuel yield and deoxygenation ability. • The interaction between metal and support would affect the deoxygenation pathway. Mo 2 N catalyst can effectively remove oxygen from biomass oil under harsh reaction conditions. Herein, the innovative Ni-Mo 2 N/γ-Al 2 O 3 catalyst was synthesized through conventional impregnation method and NH 3 or N 2 /H 2 pretreatment. The hydrodeoxygenation performance of Ni-Mo 2 N/γ-Al 2 O 3 catalyst is significantly improved in comparison with Mo 2 N. At 320 °C and 3 MPa, the oxygen of jatropha oil is completely removed and high-quality biofuel with high selectivity of C 15 -C 18 hydrocarbons are obtained over the Ni-Mo 2 N/γ-Al 2 O 3 catalyst. This good reactivity for Ni-Mo 2 N/γ-Al 2 O 3 catalyst are ascribed to the synergistic effect of Ni and Mo 2 N, the most uniform Ni dispersion and the excellent coke resistance ability. Ni, as an auxiliary, is conductive to the cleavage of H–H bonds, while Mo 2 N are beneficial to the cleavage of C–O bonds. In addition, the metal-support interaction would affect the deoxygenation pathway of jatropha oil. This research proposes an efficient strategy for enhancing the hydrodeoxygenation performance of Mo 2 N catalysts for the jatropha oil conversion. [ABSTRACT FROM AUTHOR]