On a Response Surface Analysis: Hydrodeoxygenation of Phenol over a CoMoS-Based Active Phase

Abstract

This work aims at assessing the hydrodeoxygenation (HDO) of phenol over a promising catalytic material: a CoMoS-based active phase with a Co/(Co + Mo) = 0.2, supported on a promising mixed oxide, Al2O3-TiO2 (Al/Ti = 2). Particularly, to optimize the catalytic and kinetic performance of CoMoS/Al2O3-TiO2, a response surface methodology (RSM) is carried out by following a Box–Behnken experimental design. The response variables are the initial reaction rate and the reaction selectivity, determined via a proper contribution analysis (𝜑) of both the direct hydrodeoxygenation (DDO) and the hydrogenation (HYD). At the same time, the operating conditions used as factors are the reaction temperature (280–360 °C), the total pressure (3–5.5 MPa), and the Mo loading (10–15 wt.%). The activity and selectivity are correlated to the catalysts’ physicochemical properties determined by XRD, UV-Vis DRS, TPR, and Raman Spectroscopy. Regarding the CoMo-based active phase, a Mo loading of 12.5 wt.% leads to the optimal reaction performance, which is associated with the lowest (Co + Mo)oh/(Co + Mo)th ratio. Concerning the operating conditions, a temperature of 360 °C and a total pressure of 5.5 MPa give rise to the optimal initial reaction rates, in which the DDO (𝜑 = 65%) is selectively favored over HYD (𝜑 = 35%).