Surface synergistic effects of ReNi alloy and ReOx for promoting hydrodeoxygenation of lauric acid to value-added products

[Display omitted] •Formation of a new NiReOx species with ReNi alloy core with closely adjacent ReOx.•The synergistic effect between Ni and adjacent Re species (ReOx and metallic Re) promoted lauric acid hydrodeoxygenation.•The formation of ReNi alloys improved the H2 activation capability, ReOx species facilitated lauric acid adsorption.•The product lauryl alcohol and alkanes can be selectively regulated by temperature control. The catalytic transformation of fatty acids into high-value alcohols and alkanes is a versatile technology. Herein, a bimetallic ReNi/M-TiO2-S, possessing ReNi alloy and ReOx sites, was designed and evaluated in the hydrodeoxygenation of biomass-derived fatty acids. The ReNi/ M-TiO2-S catalysts exhibited excellent hydrodeoxygenation activity for the generation of alcohol (170 °C) and alkanes (190 °C). In addition, the calcined ReNi/ M-TiO2-S catalyst displayed synergistic effect between Re-Ni oxides by XRD, Raman and H2-TPR characterizations. After reduction, NiReOx species was formed, composed of a ReNi alloy core with closely adjacent ReOx, with a synergistic effect between Ni and adjacent Re species (ReOx and metallic Re). DFT calculation, H2-TPD and in situ FTIR demonstrated that ReNi alloy improved the H2 activation capability, ReOx species promoted the adsorption of lauric acid. In addition, due to ReOx species possessing high electrophilicity, the lauric acid with highly electronegative C=O bond would be adsorbed more readily than lauryl alcohol, leading to preferential conversion of lauric acid. This study proposes the synergistic effect of ReOx and ReNi alloy and opens a new insight the development and design of promising catalysts for biomass-derived fatty acids valorization.