Solid Oxide Fuel Cells (SOFCs) offer several advantages, including the possibility to operate with bio-syngas. However, when fueled with such gas mixtures, they are exposed to trace contaminants that can strongly affect their electrochemical performance and long-term durability. The aim of this thesis is to develop and validate a zero-dimensional electrochemical model capable of describing degradation induced by selected contaminants such as sulfur compounds (COS, DMS) and siloxanes (D5). A comprehensive baseline model is first formulated under contaminant-free conditions. The model integrates detailed descriptions of activation, ohmic, and concentration losses, explicitly accounting for the simultaneous electro-oxidation of H₂ and CO at the Ni–YSZ anode.