Green hydrocarbon-range production via catalytic pyrolysis of oleic acid over MgO regulated NiO/SiO2 catalysts

Selective catalytic deoxygenation of fatty acids has been recognized as a promising approach for producing sustainable fuels. However, limited catalytic activity often results in reduced selectivity for desired products. Herein, a series of MgO-promoted NiO/SiO₂ catalysts featuring Mg-decorated NiO interfaces was synthesized for oleic acid catalytic deoxygenation to gasoline-range hydrocarbon. Detailed characterization and experiment revealed that Ni⁰ species was the active phase which could provide active H atom to enhance C-C bond cracking and hydrodeoxygenation via dissociation H₂, and Mg species introduction significant promoted NiOx species well-dispersion and enhanced oxygen vacancies content to adsorption and activate carbonyl group. Notably, 3 %-Mg promoted Ni-SiO₂ catalyst exhibited superior catalytic activity with 100 % conversion rate, 96.83 % and 54.58 % yield of hydrocarbon compound and olefins yield and 70.25 % selectivity to gasoline-range fraction via dehydration-hydrogenation process due to excellent acidity site, oxygen vacancies, texture properties and well-distribution and synergistic promoting effect of Ni and Mg species. Furthermore, coke deposition, active species reduction and leaching was reasonable for catalyst deactivation, resulting in hydrocarbon yield and olefin selectivity decreasing after five cycling. This deep understanding provided a facile strategy for catalyst rational design and the developed Mg/Ni-Si catalysts highlighted a great prospect for produce green hydrocarbon-rich fuel from biomass-derived oxygen-containing compound.