Towards production of renewable diesel over robust Ni nanoclusters highly dispersed on two-dimensional zeolite

Abstract

Abstract Deoxygenation of bio-derived lipids into renewable transportation fuels is a promising route to decrease the dependence on fossil sources. Ni-based catalysts are high performing and cost-effective in deoxygenation reactions but suffer from severe sintering and aggregation. Herein, a ligand-chelating impregnation method was applied to prepare highly dispersive Ni nanoclusters on two-dimensional (2D) ITQ-2 zeolite. Comprehensive characterization techniques were utilized to monitor the changes of organometallic precursors during activation and to investigate their impact on the dispersion of Ni nanoclusters on ITQ-2 zeolite. The 2D support with a high external surface and abundant surface defects enhances the dispersion and immobilization of the Ni nanoclusters, compared to conventional counterpart zeolites. The protection of Ni2+ cations by organic ligand can suppress the aggregation of Ni species during activation processes, thereby leading to the formation of uniformly distributed Ni nanoclusters on ITQ-2 zeolite. Beneficially from the highly dispersive Ni nanoclusters and immobilization effect of 2D zeolite, the Ni/ITQ-2 material prepared by ligand-chelating impregnation approach showed outstanding activity and stability in the conversion of stearic acid or palm oil to diesel range alkanes. This work opens a boulevard for rational design and precise modulation of metal-based catalysts for the production of renewable diesel.