Abstract & Overview
Abstract Catalyst performance is one of the most decisive aspects for adding value to the industrial prospects of the hydrodeoxygenation (HDO) of lignin-derived oils to fuels. Deactivation of the catalyst, associated with blockage of pores and active sites due to diffusion limitations and the polymerization of bulky phenolic-type compounds, presents a significant challenge. In the present study, textural properties (pore diameter and surface area) are optimized by doping Al 2 O 3 with La- and/or Ce-precursors prior to inducing a phase transformation and pore coarsening through heat exposure. Response surface methodology and analysis of variance were applied to evaluate the optimal ratios (between 0 and 5 wt%) of the dopants to maximize the pore diameter while preserving the surface area for three different impregnation approaches. The dopants were either impregnated simultaneously or separately and calcined at 1100 °C–500 °C. Finally, the overall performance of synthesized Ni-Mo catalysts, supported on doped Al 2 O 3 , for the HDO process of vanillin under continuous-flow conditions ( T = 314 °C, P = 5 bar(g), and WHSV = 35 h − 1 ) was assessed. Statistically significant regression models for tuning the textural properties of the supports were developed, showing that a maximized pore diameter is obtained by doping with 5 wt% La. However, the findings of this study indicate that Ni-Mo/Al 2 O 3 catalysts doped with 1 wt% La and 1 wt% Ce are favored for the direct HDO process. An additional beneficial aspect is the low amount of carbon deposition on these catalysts.