Influence of Ni catalyst support on the product distribution of cellulose fast pyrolysis vapors upgrading

Abstract In this work, an influence of Ni catalyst support on the product distribution in the upgrading of cellulose fast pyrolysis vapors was investigated. The catalysts containing 20% of Ni introduced by impregnation on Al₂O₃, SiO₂, MgO, CeO₂ and ZrO₂ surface were prepared. In the case, of the zirconium oxide synthesis three different methods of support preparation were applied. The effects of surface acidity, type of the precursor and support preparation method, crystalline phase of the support, interactions between active phase and support, surface area of the catalyst and NiO crystallite size on the distribution of reaction products were studied. Moreover, an impact of CaO addition to the Ni/ZrO₂ catalysts was evaluated. The composition of reaction products was identified using Py-GC/MS. The surface properties of the investigated catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and temperature-programmed reduction (TPR). Acidity and surface area of the catalysts were also determined. The obtained results, revealed that while surface acidity exerts a significant impact on the reaction yield, other factors can also considerably change the distribution of products in the upgrading of vapors from cellulose fast pyrolysis.