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

Abstract

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 N2 adsorption-desorption, X-ray diffraction (XRD), H2 chemisorption, H2 temperature-programmed reduction (H2-TPR), NH3 temperature-programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS). The Ni−Ce0.6Zr0.4O2 catalyst calcined at 300 °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.