FEATURES
A
merica consumes twenty percent of all oil produced in the world despite being the home of less than five percent of the world’s population1. Our dependence on oil creates economic and political pressures, as we have seen with recently inflated gas prices2. When these concerns are compounded by the damaging environmental effects of oil extraction, transport, and use, it is easy to understand why the U.S. is turning toward alternative fuel sources. Hydrogen fuel cells are one of the most promising alternatives that has been researched over the last few decades.
These advantages have motivated researchers and engineers to explore and refine the processes and technologies that are essential to hydrogen fuel cells. Many different types of hydrogen fuel cells have been developed, including alkali fuel cells, molten carbonate fuel cells (MCFC), and proton exchange membrane fuel cells (PEMFCs)4. These are all variations of the same fundamental process of reacting hydrogen and oxygen to generate power. To better understand how these fuel cells work, one can study PEMFCs, which many scientists believe to be a promising candidate for use in homes and vehicles.
These fuel cells have several advantages over conventional fossil fuels3. One such advantage is the ability to generate power without combustion or carbon emissions. Even if one were to account for emissions due to production, when measured against gasoline vehicles, vehicles that utilize fuel cells are able to reduce their total carbon dioxide by half if the hydrogen is produced by natural gas and by 90% if the hydrogen is produced by renewable sources. Other upsides include the accessibility of hydrogen and oxygen in our atmosphere and the ability to be electrical grid-independent, which is especially important for critical load functions such as hospitals and military applications.
There are four main components to a PEMFC: the anode, the cathode, the electrolyte, and the catalyst5. Respectively, the anode and cathode are negative and positive electrodes (conductors that connect nonmetallic materials to a circuit). That is, both the anode and cathode are the mechanisms with which electrons are directed throughout the fuel cell. They also have channels which are responsible for distributing gases evenly across the catalyst6. Next, the electrolyte, commonly referred to as the proton exchange membrane, functions by conducting positive charges. Lastly, the catalyst is where the hydrogen and oxygen reactions occur. It is engineered from carbon paper or cloth coated with platinum nanoparticles.
Fueling A e r u t u F r e N Clean han Tra by Jonat ng Ngo Written by Phuo d e n ig s e D
22 PENNSCIENCE JOURNAL | Spring 2022
HYDROGEN STATION
H
