A simple fabrication of mineral supported Ni-NiAl2O4 nanocomposites with a novel transition layer

Abstract

In recent years, Ni-based catalysts have attracted widespread attention in many fields due to their low price and high catalytic activity. However, the low dispersion of active components has significantly restricted their large-scale application. In this work, we prepared a new type of sepiolite nanofibers loaded Ni-NiAl 2 O 4 composite by coupling the sol-gel and reduction methods, using nickel nitrate, aluminum nitrate and sepiolite nanofibers as the raw materials. To determine the optimal conditions for preparing the composite material, the effects of complexing agent, additives, sepiolite addition content, calcination temperature and time, and reduction temperature and time on the microstructure of the composite were systematically studied. With comprehensive characterizations, the optimal preparation conditions of the composite were determined. In the optimal composite, the NiAl 2 O 4 nanoparticles with a particle size of ~25 nm were uniformly dispersed on the sepiolite surface, and nickel nanoparticles with a size of 5 nm and well dispersion were rooting in the NiAl 2 O 4 particles. The NiAl 2 O 4 in the composite was acted as the nickel source and transition layer for the growth and dispersion of nickel particles, respectively. This work is expected to provide an effective strategy for the low-cost preparation of Ni-based catalysts, in which the novel transition layer can provide stable nickel particles with good dispersion. • A novel mineral supported nickel-based catalyst was prepared via a sol-gel reduction method. • Comprehensive characterizations were performed on the prepared materials. • The dispersion of NiAl 2 O 4 nanoparticles can be improved by sepiolite. • The NiAl 2 O 4 as a transition layer can provide nickel source for the subsequent reduction process.