 The efficiency of Ni-TO2 catalysts for renewable diesel production was evaluated in the present study. Two series of catalysts were synthesized and characterized using various physical chemical techniques, N2-physisorption, XRD, SEM, XPS, H2-TPR, and NH3-ATPD. In the first series of catalysts, successive dry impregnations, SDI, were used for depositing 10, 20, 30, 50, and 60 weight percent Ni. The yield towards renewable diesel is maximized over the catalyst with 50 weight percent Ni loading. Selecting this optimum loading, a second series of catalysts were synthesized via three additional preparation methods, wet impregnation, WI, and deposition precipitation using either ammonia, DP-NH3, or urea, DP-Urea, as the precipitation agent. The catalysts' efficiency in the production of green diesel is influenced by the preparation method following the order, DP-Urea, DP-NH3. This article was authored by George Petropoulos, John Zephyropoulos, Iliana Cordulli, and others.