Boosting bio-lipids hydrodeoxygenation via highly dispersed and coking-resistance bimetallic Ni-La/SiO2 catalyst

A highly dispersed and coking-resistance bimetallic Ni-La/SiO 2 catalyst was prepared for the selective hydrodeoxygenation (HDO) of fatty acid methyl esters (FAMEs) and non-edible bio-lipids to hydrocarbon compounds. Under optimum conditions, full conversion of methyl palmitate (MP) and 97.6 % selectivity for pentadecane (PD) were achieved. The catalyst also exhibited high conversion and excellent desired product selectivity for the HDO of various model FAMEs, fatty acids, trilaurin , jatropha oil (JO) and waste cooking oil (WCO). Multiple characterizations show that the embedding effect (metal−support or metal−metal interaction) associated with the introduction of metallic La not only contributes to the formation of well-dispersed Ni particles and abundant active Ni δ+ −O V −LaO x species, but also prevents the migration and sintering of metallic Ni particles at high temperatures. Furthermore, the mutual transformation of the La 2 O 3 and La 2 O 2 CO 3 crystal phases effectively inhibits coke deposition on the catalyst surface during the reaction process, resulting in remarkable stability and reusability of the catalyst. A plausible reaction network and mechanism for the catalytic HDO of MP over Ni-La/SiO 2 catalyst were proposed. This method of constructing a catalytic system can provide a basis for the development of efficient catalysts for the HDO of non-edible bio-lipids. • A dispersed, sintering- and coking-resistance Ni-La/SiO 2 catalyst is prepared. • Embedding effect of La aids in the formation of diffuse Ni and active Ni δ+ -O V -LaO x . • Intertransformation of La 2 O 3 and La 2 O 2 CO 3 potently removes coke deposition. • Superb conversion and selectivity for HDO of bio-lipids are achieved. • A reaction network and mechanism for the HDO of methyl palmitate is proposed.