Modifying the active phase structure of Ni2P/Al2O3 by Ga introduction for improved hydrodesulfurization of diesel

Abstract

Modifying the structure of active phase is an effective protocol to improve the catalytic activity of hydrodesulfurization (HDS) catalyst. Here, a variety of mesoporous GaAlOx supports with various Ga doping amount were synthesized by a facile hydrothermal strategy. The corresponding Ni2P supported catalysts were fabricated via a conventional impregnation and temperature-programmed reduction method, and their catalytic performances for 4,6-DMDBT HDS were examined. The experimental analyses show that the introduction of Ga substantially influences the geometric and electrical structure of Ni2P active phase on Ni2P/GaAlOx catalysts. The metal-support interaction is effectively abated with the elevation of Ga doping amount, thereby increasing the d-electron density of Ni species and boosting the pre-hydrogenation (HYD) route, thereupon enhancing the HDS performances of corresponding Ni2P/GaAlOx catalysts. Therein, Ni2P/GaAlOx-0.50 exhibits the highest activity with 70.1% 4,6-DMDBT conversion because of the optimal morphology and percentage of active phase, as well as distinguished redox and acid property. Further increasing the Ga loading, however, inhibits the HDS activity of Ni2P/GaAlOx-1.0 catalyst due to the decrease in the fraction and dispersion of active phases. Therefore, this work may shine light on the understanding of structure–activity of HDS catalyst and thereafter the preparation of HDS catalysts with high efficiency in future.