Effect of calcination temperature on the association between free NiO species and catalytic activity of Ni-Ce0.6Zr0.4O2 deoxygenation catalysts for biodiesel production

In this study, a series of Ni-Ce0.6Zr0.4O2 catalysts, which were synthesized by co-precipitation followed by calcination at different temperatures, were applied for the deoxygenation of oleic acid. The physicochemical properties of the catalysts were characterized by N-2 adsorption-desorption, X-ray diffraction (XRD), H-2 chemisorption, H-2 temperature-programmed reduction (H-2-TPR), NH3 temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS). The Ni-Ce0.6Zr0.4O2 catalyst calcined at 300 degrees C exhibited the highest conversion for oleic acid as well as selectivity for diesel range compounds. It is predominantly related to the highest amount of free NiO species. In addition, the acidity of the catalyst significantly affected the selectivity and distribution of products. (C) 2018 Elsevier Ltd. All rights reserved.