The in-situ fabrication of metal sites and distinct oxygen vacancies over the Ni-ZrO2 deoxygenation catalyst

The deoxygenation of natural oils is the most mature technology for bio-aviation fuel production. The Ni-ZrO 2 catalyst has been widely researched for the deoxygenation reaction whose catalytic behavior is largely determined by Ni dispersion and oxygen vacancy (Ov) concentration. However, few studies succeed in controlling these two critical factors simultaneously, which hinders further improvement in performance. Herein, an in-situ grinding synthesis method was developed for simultaneous doping of Ni 2+ into ZrO 2 lattice to generate more Ov (O V -Ni-ZrO 2 ) and fabrication of dispersed Ni nanoparticles over the Ni-ZrO 2 catalyst. It involved grinding of nickel source and ZrO 2 precursors followed by crystallization, thus avoiding extra solvents. DFT calculations indicate that doping of Ni 2+ promotes formation of O V -Ni-ZrO 2 which exhibits stronger adsorption capacity toward fatty acid ester and oxygen-containing intermediates than those on pure ZrO 2 (O V -ZrO 2 ). Besides, more Ov-Ni-ZrO 2 interface species and basic (acid) sites are generated over the Ni-ZrO 2 catalyst. The deoxygenation of methyl laurate (ML) proceeds through hydrogenolysis of ML into CH 4 and lauric acid followed by decarbonylation to alkanes. The synergetic effect between dispersed Ni and abundant O V endows the Ni-ZrO 2 catalyst with complete conversion and C 9 -C 12 alkanes yield of 93.2 % in deoxygenation of ML, outperforming the impregnated counterpart significantly.