ReOx promotes Ni cluster interactions on TiO2 to improve the activity and durability for green alkane and alcohol production at low temperature

Abstract

Enhancing both the reactivity and stability of catalysts for the hydrogenation of bio-derived fatty acids is a formidable challenge. In this study, we developed a Ni-ReO_x/TiO₂ catalyst, featuring Ni metal clusters encapsulated by ReO_x active sites anchored on the TiO₂ surface, for the hydrogenation of bio-derived fatty acids. Remarkably, the Ni-ReO_x/TiO₂ catalyst with a relatively low Re loading (approximately 4.4 wt%) exhibited outstanding performance in fatty alcohol production at a reduced temperature of 165 °C (yield: 95.3%) and alkane production at 205 °C (yield: 100.0%), outperforming the Cu-ReO_x/TiO₂ catalyst. Density functional theory (DFT) calculations unveiled that the introduction of ReO_x onto the anatase surface led to modifications in electronic distribution and enhanced the interaction between the support and the metal. By integrating the DFT calculations with experimental results, we elucidated the roles played by the Ni clusters and Re–O active sites in the Ni-ReO_x/TiO₂ catalyst: facilitating H₂ dissociation, promoting acid adsorption, and ultimately contributing to acid hydrogenation conversion. The industrial-scale processes for alkane and alcohol production were designed and simulated using Aspen Plus, enabling a quantitative assessment of the remarkable reaction activity of the Ni-ReO_x/P25 catalyst. Additionally, the Ni-ReO_x/P25 catalyst demonstrated excellent stability over four recycling cycles, coupled with robust water tolerance, thus showcasing its immense potential for application in industrial fuel and fatty alcohol production.