Comparison of Non-noble Metal Catalysts in Lipid Hydrotreatment into Second-Generation Bio-diesel

To explore a green, cheap, and high-performance catalyst for lipid hydrotreatment into green diesel, the non-noble metal catalysts (Fe, Cu, Co, Ni, and Mo) with Al 2 O 3 carrier were prepared. Their catalytic performance in oleic acid hydrotreatment was compared, and the metal loading was studied. The characterizations (XRD, N 2 physical sorption, H 2 -TPR, and XPS) were utilized to elucidate the catalytic property. In oleic acid hydrotreatment, the catalytic activity of 5 monometallic catalysts was in the following order: Co > Mo > Ni > Fe > Cu, and the Co/Al 2 O 3 catalyst achieved 94.4% conversion and 91.8% alkane yield. Among 6 Co loadings (5, 10, 15, 20, 25, and 30 wt%), 25 wt% was optimal because it reached the balance of the surface area and the number of Co active sites. Moreover, the lipid hydrotreatment over Co/Al 2 O 3 catalyst occurred mainly via DCX/DCN route; meanwhile, the cracking reaction also happened. Graphical Abstract