Toward the production of renewable diesel over robust Ni nanoclusters highly dispersed on a two-dimensional zeolite

Abstract

Deoxygenation of bioderived lipids into renewable transportation fuels is a promising route to decreasing 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 used to prepare highly dispersed Ni nanoclusters on a two-dimensional (2D) ITQ-2 zeolite. Comprehensive characterization was utilized to monitor the changes in the organometallic precursors during activation and to investigate their impact on the dispersion of the Ni nanoclusters on the ITQ-2 zeolite. The high external surface area and abundant surface defects of the 2D support enhanced the dispersion and immobilization of the Ni nanoclusters and outperformed conventional zeolites. The protection of the Ni2+ cations by the organic ligand suppressed the aggregation of Ni species during the activation processes, thereby leading to the formation of uniformly distributed Ni nanoclusters on the ITQ-2 zeolite. Due to the highly dispersed Ni nanoclusters and immobilization on the 2D zeolite, the Ni/ITQ-2-co material prepared by the ligand-chelating impregnation approach showed outstanding activity and stability for conversions of stearic acid or palm oil to diesel range alkanes. This work provides a rational design and precise modulation of metal-based catalysts for the production of renewable diesel.

Construction of Metal/Zeolite Hybrid Nanoframe Reactors via in-Situ-Kinetics Transformations

“…Additionally, heptadecane can be obtained through the metal-catalyzed decarboxylation of stearic acid or the hydrodecarbonylation of octadecanal. The acidic sites in the zeolite induce hydroisomerization and hydrocracking of alkanes, resulting in the production of iso-octadecane and iso-heptadecane. − In general, the narrow micropores in zeolites impose diffusion limitations on large stearic acid molecules, thus restricting accessibility to internal acid and embedded metal sites within conventional metal/zeolite catalysts. Therefore, the ZSM-5@Ni/SiO 2 NFs are expected to show improved catalytic performance because of excellent mass transfer efficiency and accessible abundant bifunctional metal/acid sites. , Besides ZSM-5@Ni/SiO 2 NFs, the Ni-loaded ZSM-5 nanocrystals (ZSM-5@Ni/SiO 2 NCs), Ni-loaded ZSM-5 nanoboxes (ZSM-5@Ni/SiO 2 NBs, Figure S17), and impregnation-prepared Ni-loaded ZSM-5 nanoframes (IM-Ni/ZSM-5 NFs) with similar Ni content and Si/Al ratio were used as reference catalysts for comparative analysis.…”

Conversion of Polyethylene to Low-Molecular-Weight Oil Products at Moderate Temperatures Using Nickel/Zeolite Nanocatalysts

“…It is presumed that the relatively high amount of phosphorus of the EDS data occurs because the phosphorus of trioctylphosphine used as ligands for the nanoparticles remains after calcination. The size of the nickel nanoparticles on the zeolite surface ranged from approximately 10 to 30 nm, indicating that some slight agglomeration occurred during the calcination process, but they still exhibited a smaller size distribution compared to conventional catalysts [41,42].…”