Quantum mechanics

Magnetic field

Engineering

Faraday cage

Electrochemistry

Materials science

Crossover

Polymer electrolyte membrane electrolysis

High-pressure electrolysis

Computer science

Faraday efficiency

Electrolysis of water

Current (fluid)

Physical chemistry

Thermodynamics

Hydrogen

Physics

Nuclear engineering

Organic chemistry

Artificial intelligence

Chemistry

Electrode

Anode

Hydrogen production

Electrolyte

Electrolysis

Energies

In electrolyzers, Faraday’s efficiency is a relevant parameter to assess the amount of hydrogen generated according to the input energy and energy efficiency. Faraday’s efficiency expresses the faradaic losses due to the gas crossover current. The thickness of the membrane and operating conditions (i.e., temperature, gas pressure) may affect the Faraday’s efficiency. The developed models in the literature are mainly focused on alkaline electrolyzers and based on the current and temperature change. However, the modeling of the effect of gas pressure on Faraday’s efficiency remains a major concern. In proton exchange membrane (PEM) electrolyzers, the thickness of the used membranes is very thin, enabling decreasing ohmic losses and the membrane to operate at high pressure because of its high mechanical resistance. Nowadays, high-pressure hydrogen production is mandatory to make its storage easier and to avoid the use of an external compressor. However, when increasing the hydrogen pressure, the hydrogen crossover currents rise, particularly at low current densities. Therefore, faradaic losses due to the hydrogen crossover increase. In this article, experiments are performed on a commercial PEM electrolyzer to investigate Faraday’s efficiency based on the current and hydrogen pressure change. The obtained results have allowed modeling the effects of Faraday’s efficiency by a simple empirical model valid for the studied PEM electrolyzer stack. The comparison between the experiments and the model shows very good accuracy in replicating Faraday’s efficiency.

Faraday’s Efficiency Modeling of a Proton Exchange Membrane Electrolyzer Based on Experimental Data