Hydrodechlorination and hydrodearomatisation of monoaromatic chlorophenols into cyclohexanol on Ru/C catalysts applied to water depollution: influence of the basic solvent and kinetics of the reactions

Catalytic hydrodechlorination and hydrodearomatisation of 13 different mono-, di-, tri-, tetra- and pentachlorophenols were carried out simultaneously under mild reaction conditions (298–353 K, 0.3–0.5 MPa). Experimental conditions suitable for complete conversion of the pollutants into nontoxic cyclohexanol and sodium chloride were first determined using a commercial Ru/C catalyst. A new supported ruthenium catalyst was then designed that possesses a carbonaceous support suitable to concentrate chlorophenol through adsorption. Using parachlorophenol as a model molecule, the influence of the base concentration in solution and the kinetics of the reaction under chemical regime were studied. A p-chlorophenol→phenol→cyclohexanol consecutive kinetic scheme was considered that drove to numerous possible kinetic models. A dynamic simulation software was used both for helping in model discrimination and for kinetic parameter estimation. The estimated activation energy values amount to ca. 45.0±2.7 and 33.2±2.4 kJ mol−1 for the hydrodechloration and the hydrodearomatisation steps, respectively.