A mathematical model of the electrocatalytic hydrogenation of phenol on a Pd/Al2O3 (10%, W/W) Catalyst is developed and presented from the chemical kinetic to the fluid mechanical point of view in a laboratory scale cell. The model includes the heterogenous electrochemical steps at the microscopic scale, integrated in a full transient, three-dimensional representation of the fluid mechanics and species concentration in the electrochemical cell. In this reactor, the catalytic particles are dispersed and recirculated in the solution. The brief contact of the powder with a porous reticulated vitreous carbon is sufficient to obtain adsorbed hydrogen on the nanoaggregates who contains the phenol adsorbed. The isotherm of Langmuir and the pseudo-second-order model, based on assumption of second-order mechanism are developed. The aim of this work is to understand and validate the pseudo-second-order adsorption model when used with hydrogen adsorption isotherm, and to develop a full model of the electrochemical cell. The proposed model could be used to improve the design of industrial scale reactors. The model is validated using experimental results from [A. Bannari, C. Cirtiu, F. Kerdouss, P. Proulx, H. Menard, Chem, Eng. Process. 45 (2006) 471]. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.