Novel fabrication of a sepiolite supported cobalt-based catalyst via a coprecipitation-reduction method

In this work, a novel supported cobalt-based catalyst Co-CoAl2O4/sepiolite was successfully prepared via a coprecipitation-reduction method. The nanocomposites were examined by various surface characterization techniques to explore the optimal preparation conditions which were found to be: 750 °C for the calcination temperature, 9 for the pH value of the precursor, 7.5:1 for the mass ratio of the metal salt to sepiolite and 650 °C for the reduction temperature. The introduction of sepiolite not only reduced the calcination temperature of forming spinel CoAl2O4, but also improved the distribution of the CoAl2O4 nanoparticles, which provided more active sites to support Co nanoparticles produced via the reduction of the CoAl2O4/sepiolite composite subsequently. Moreover, the existence of CoAl2O4 as a transition layer provided a cobalt source for the subsequent reduction process and increased the service life of the catalyst. This work is believed to provide a new strategy for designing low cost and efficient cobalt-based catalysts.