In the journey toward a carbon-neutral society, hydrogen has become an integral and necessary component for energy storage and power generation. Fuel Cells (FCs), including Proton Exchange Membrane (PEM) types are an auspicious clean power source that can be used in various applications, such as automotive and stationary power systems. PEMFC converts hydrogen into electricity, water, and heat, with an electric efficiency that can reach up to 60% [1]. Despite the promising potential of fuel cell technology, it confronts significant challenges in terms of economics in the case of mass commercialization [2], as well as low reliability and short durability, with an average operation time of 3800 hours and 11900 hours for transport and stationary applications, respectively [3]. Therefore, a deep understanding of the physical phenomena and mechanisms involved in the operation and degradation of PEMFC is required for their optimization to overcome the mentioned technical limitations. Several models are currently proposed in the literature, including semi-empirical zero-dimensional (0D) models [4-7]. However, these models fail to offer a fundamental comprehension of PEMFC operation, and existing tradeoffs in predicting performance or enhancing design across diverse operating conditions are restricted [8]. More inclusive models, such as the one-dimensional (1D) models, incorporate mass transfer processes in a linear direction perpendicular to the FC sandwich [8]. Moreover, not all models undergo verification with primary experimental data, and some rely on existing secondary data from literature [9-10]. This paper begins by analytically deriving the governing equations for the fuel cell in a single geometrical dimension (1D). Then it employs MATLAB Software to model thermal, charge, mass transport, and electrochemical processes. Additionally, it utilizes ANSYS Fluent software to perform a 3D model extension at a cell and short stack level by applying the finite volume method. The validation is performed on a 5kW PEMFC stack that is accessible at the International University of Rabat (UIR) Renewable Energies and Advanced Materials Laboratory (LERMA) and tested against various literature-sourced data. References: [1] Luo, Yu, et al. “Bridging a Bi-Directional Connection between Electricity and Fuels in Hybrid Multienergy Systems.” Hybrid Systems and Multi-Energy Networks for the Future Energy Internet, 2021, pp. 41–84, https://doi.org/10.1016/b978-0-12-819184-2.00003-1. [2] Guerrero Moreno, N., Cisneros Molina, M., Gervasio, D., & Pérez Robles, J. F. (2015, December). Approaches to polymer electrolyte membrane fuel cells (PEMFCs) and their cost. Renewable and Sustainable Energy Reviews, 52, 897–906. https://doi.org/10.1016/j.rser.2015.07.157. [3] Stropnik, R., Mlakar, N., Lotrič, A., Sekavčnik, M., & Mori, M. (2022). The influence of degradation effects in proton exchange membrane fuel cells on life cycle assessment modelling and environmental impact indicators. International Journal of Hydrogen Energy, 47(57), 24223–24241. https://doi.org/10.1016/j.ijhydene.2022.04.011. [4] Amphlett, J. C., et al. “Performance Modeling of the Ballard Mark IV Solid Polymer Electrolyte Fuel Cell: I . Mechanistic Model Development.” Journal of the Electrochemical Society, vol. 142, no. 1, 1 Jan. 1995, pp. 1–8, https://doi.org/10.1149/1.2043866. [5] Mann, Ronald F., et al. “Development and Application of a Generalised Steady-State Electrochemical Model for a PEM Fuel Cell.” Journal of Power Sources, vol. 86, no. 1-2, Mar. 2000, pp. 173–180, https://doi.org/10.1016/s0378-7753(99)00484-x. [6] Choi, J., Sim, J., Oh, H., & Min, K. (2021). Resistance separation of polymer electrolyte membrane fuel cell by polarization curve and electrochemical impedance spectroscopy. Energies, 14(5), 1491. https://doi.org/10.3390/en14051491. [7] Wishart, J., Dong, Z., & Secanell, M. (2006). Optimization of a PEM fuel cell system based on empirical data and a generalized electrochemical semi-empirical model. Journal of Power Sources, 161(2), 1041–1055. https://doi.org/10.1016/j.jpowsour.2006.05.056. [8] Yang, F., Xu, X., Li, Y., Chen, D., Hu, S., He, Z., & Du, Y. (2023). A review on Mass transfer in multiscale porous media in proton exchange membrane fuel cells: Mechanism, modeling, and parameter identification. Energies, 16(8), 3547. https://doi.org/10.3390/en16083547. [9] Asl, S. S., Rowshanzamir, S., & Eikani, M. H. (2010). Modelling and simulation of the steady-state and dynamic behaviour of a PEM fuel cell. Energy, 35(4), 1633–1646. https://doi.org/10.1016/j.energy.2009.12.010. [10] Shah, A. A., & Walsh, F. C. (2008). A model for hydrogen sulfide poisoning in proton exchange membrane fuel cells. Journal of Power Sources, 185(1), 287–301. https://doi.org/10.1016/j.jpowsour.2008.06.082