Aqueous Phase Hydrodeoxygenation of Phenol over Ni₃P-CePO₄ Catalysts

Abstract

Unsupported Ni 3 P-CePO 4 catalysts were prepared by coprecipitation, followed by drying, calcination, and temperature-programmed reduction. The prepared catalysts were characterized by XRD, N 2 adsorption−desorption, TEM, STEM-EDS elemental mapping, XPS, NH 3 -TPD, FT-IR of adsorbed pyridine, and H 2 -TPR. Their catalytic performances in hydrodeoxygenation (HDO) were investigated using an aqueous solution of phenol (5.0 wt %) as the feed. CePO 4 was generated in coprecipitation and stable in the subsequent drying, calcination, and temperature-programmed reduction (final temperature 500 °C). It is shown that the addition of CePO 4 resulted in enhanced HDO activity, and a maximum activity appeared at a Ce/Ni ratio of 0.3. The presence of CePO 4 improved the dispersion of Ni 3 P significantly, leading to enhanced hydrogenation activity. CePO 4 served as the major dehydration sites as well because of its surface acidity (mainly Lewis acid). In addition, the kinetics of the aqueous phase HDO of phenol and cyclohexanol catalyzed by Ni 3 P and by Ni 3 P-CePO 4 with Ce/Ni ratio of 0.3 were investigated.

Effects of Crystallite Sizes of Pt/HZSM-5 Zeolite Catalysts on the Hydrodeoxygenation of Guaiacol

“…To determine the reaction rate of guaiacol conversion, we measured the product selectivity as a function of the reaction time. It has been shown previously that the HDO of phenolic compounds conducted in the excess of H 2 represents a first-order reaction with respect to the reactant concentrations [ 45 ]. Therefore, the product formation rates were expressed according to the simplified model presented below, where k i was the reaction rate constant, and x i was the molar fraction of a product.…”

Highly Selective Hydrodeoxygenation of Dibenzofuran into Bicyclohexane over Hierarchical Pt/ZSM-5 Catalysts

“…Because of the complexity of DBF conversion, the number of reactions, and the multiple products, quantitative data about characterizing kinetic model parameters are restricted. In order to simplify the analysis, the first-order reaction for the main product was assumed according to the literature of catalytic hydrodeoxygenation. − The pseudo-first order model for DBF reaction was employed by eq where x and τ represent the conversion of DBF and the molar mass of the reactant transformed per unit mass and unit time, respectively.…”

Mild Hydrodeoxygenation of Phenols into Cycloalkanes under Ambient Hydrogen Pressure over a Ni/H‐Beta Catalyst

“…Previously, Lercher reported the HDO at 200–300 °C using Ni/H‐ZSM‐5 catalyst or a catalyst system consisting of Raney Ni and Nafion/SiO 2 . Wang reported the reaction at 250–350 °C with Ni 3 P/CePO 4 catalyst . Liang developed a NiNb oxide catalyst for the HDO at 150–240 °C .…”

“…[13] Wang reported the reaction at 250-350 °C with Ni 3 P/CePO 4 catalyst. [14] Liang developed a NiNb oxide catalyst for the HDO at 150-240 °C. [15] Zhang reported the HDO at 200 °C by a catalyst system using a cobalt nitride supported on a nitrogen-doped carbon (CoN x @NC) and H-ZSM-5.…”